Ex-FBI Agent Cites High-Level Dysfunction Over 9/11

Ex-F.B.I. Agent Cites High-Level Dysfunction Over 9/11

http://www.nytimes.com/2011/09/12/us...&smid=fb-share

By SCOTT SHANE
Published: September 11, 2011

WASHINGTON — In a new memoir, a former F.B.I. agent who tracked Al Qaeda before and after the Sept. 11 attacks paints a devastating picture of rivalry and dysfunction inside the government’s counterterrorism agencies. The book describes missed opportunities to defuse the 2001 plot, and argues that other attacks overseas might have been prevented, and Osama bin Laden found earlier, if interrogations had not been mismanaged.

Ten years after the attacks of Sept. 11, 2001, a special report on the decade’s costs and consequences, measured in thousands of lives, trillions of dollars and countless challenges to the human spirit.

The account offered by the agent, Ali H. Soufan, is the most detailed to date by an insider concerning the American investigations of Al Qaeda and the major attacks that the group carried out, including bombings of American Embassies in East Africa and the American destroyer Cole, as well as the Sept. 11 attacks. The book is scheduled to be published Monday, with redactions to several chapters by the Central Intelligence Agency, the target of much of Mr. Soufan’s criticism.

In the 571-page book, “The Black Banners: The Inside Story of 9/11 and the War Against Al Qaeda,” Mr. Soufan accuses C.I.A. officials of deliberately withholding crucial documents and photographs of Qaeda operatives from the F.B.I. before Sept. 11, 2001, despite three written requests, and then later lying about it to the 9/11 Commission.

He recounts a scene at the American Embassy in Yemen, where, a few hours after the attacks on New York and Washington, a C.I.A. official finally turned over the material the bureau requested months earlier, including photographs of two of the hijackers.

“For about a minute I stared at the pictures and the report, not quite believing what I had in my hands,” Mr. Soufan writes. Then he ran to a bathroom and vomited. “My whole body was shaking,” he writes. He believed the material, documenting a Qaeda meeting in Malaysia in January 2000, combined with information from the Cole investigation, might have helped unravel the airliner plot.

Mr. Soufan recounts how he began a promising interrogation of a knowledgeable Qaeda member, Abdullah Tabarak, at Guantánamo Bay, Cuba, only to be told by the military authorities that he could no longer speak to the prisoner. He later learned the prisoner was sent to Morocco and subsequently released.

On another occasion, he questioned a Yemeni Qaeda operative known as al-Batar who had once carried money for Bin Laden as a dowry for the terrorist leader to marry a young Yemeni woman. The prisoner gave him some information, but said he would tell the rest of his story only if he was allowed to make a phone call to his family — a request the Pentagon denied. The interrogation was cut off, losing what Mr. Soufan regarded as a possible lead on the whereabouts of Bin Laden.

After a C.I.A. officer disobeyed her bosses’ instructions and gave Mr. Soufan 45 minutes to question Ramzi Binalshibh, one of the 9/11 conspirators, and another unidentified prisoner, Mr. Soufan and his colleagues learned of a plot to bomb an oil tanker off the Yemeni port of Al Mukalla. But their memo was ignored, and a few weeks later the French tanker Limburg was attacked, killing one crew member and wounding 12 others.

Mr. Soufan writes that the most consequential mistake of all was the C.I.A.’s embrace of brutal tactics for interrogation, which Mr. Soufan says were directed from the Bush White House and opposed by some C.I.A. officers. The book calls the interrogation of Abu Zubaydah, the first important prisoner questioned by the C.I.A., as a fateful wrong turn toward torture and away from what he considered more effective traditional interrogation methods.

A C.I.A. spokesman, Preston Golson, said the agency had ordered redactions to the book only to protect classified information, not to strike back at the author. Still, he said, “With all due respect to Mr. Soufan, the Central Intelligence Agency has a very different assessment, as you might expect, on these events.”

He called “baseless” the assertion that the agency “purposely refused to share critical lead information on the 9/11 plots.” And without addressing the agency’s harsh interrogations, which were banned by President Obama in 2009, he said the C.I.A. “has significantly degraded Al Qaeda” and has produced intelligence that allowed the United States and others “countless times to save lives and disrupt plots.”

Mr. Golson said the accusations contained in the book “diminish the hard work and dedication of countless C.I.A. officers who have worked tirelessly against Al Qaeda both before and after 9/11 — hard work that culminated in the operation that found Bin Laden.”

Mr. Soufan said in an interview that he had the highest respect for many of the C.I.A. officers he worked with in the field. “Unfortunately, there were people in Washington making decisions out of fear,” he said. While the C.I.A.’s interrogation program produced a great deal of valuable information, he said, it did so despite the use of brutality, not because of it.

“There are some politicians and bureaucrats who live in an alternate universe, who are invested in that small part of the program and defend it regardless of facts,” he said.

The use of coercion prompted the F.B.I. director to ban his agents from C.I.A. interrogations, Mr. Soufan noted, meaning that some of the government’s most knowledgeable experts were unable to speak with the most important terrorists.

“Professional interrogators, intelligence operatives and investigators were marginalized, and instead of tried and tested methods being used, faith was placed in E.I.T.’s,” or “enhanced interrogation techniques,” the government’s euphemism for waterboarding and other harsh methods, he writes.

Mr. Soufan, who was born in Lebanon and is a native Arabic speaker, recounts interrogations that he conducted without physical abuse, building a rapport with terrorist suspects who gave extensive information about Al Qaeda. By his account, he disarmed prisoners by addressing them in their native language, using their family nicknames, surprising them with details they did not expect him to know and bringing them their favorite foods. He sparred with them over their interpretation of the Koran. He tricked them into talking by persuading them that their associates had already talked. He showed one prisoner a doctored photograph and persuaded another that a colleague was a “human polygraph” who could tell when the prisoner was lying.

The book also gives an account, gathered from Qaeda operatives whom Mr. Soufan questioned at Guantánamo Bay, of Bin Laden’s conduct at his camp in Afghanistan as the 9/11 plot was carried out. The Qaeda aides described Bin Laden as “especially excitable” that day, and only a few people in his entourage knew why.

As the hijacked airliners neared their targets, he asked an aide to get a Western news channel on the satellite television in his van. But the aide, Ali al-Bahlul, could not get a signal. So they turned to the radio, Mr. Soufan was told, switching between Voice of America and the BBC, and then cheering and firing their guns in the air at the first bulletin announcing that a plane had hit the World Trade Center.

The Interrogator

http://www.cbsnews.com/stories/2011/...20104378.shtml

9/11/2011

On the tenth anniversary of 9/11, "60 Minutes" brings you the story of someone who has never shown his face on television before - and for good reason. Ali Soufan was one of the FBI's secret weapons in its fight against al Qaeda. A Lebanese-American, fluent in Arabic, he interrogated al Qaeda prisoners at secret locations all over the world. Soufan was known for his ability to outwit terrorists and he's telling his story in a new book called "The Black Banners." Parts of the book have been blacked out because the CIA says they contain classified information.

On the day of the September 11 attacks, Ali Soufan was thousands of miles away from Ground Zero, but in a unique position to help find those responsible.

"What was your first thought?" correspondent Lara Logan asked.

"It was al-Qaeda," Soufan replied. "I had no doubt in my mind."

On 9/11, FBI agent Ali Soufan was in Yemen, where his New York-based team had been investigating the deadly al Qaeda attack a year earlier on the USS Cole. Soufan and his team were preparing to fly back to New York when FBI headquarters ordered him and his partner to stay put.

Soufan told Logan that he was desperate to return to New York and wanted

to investigate the Cole at another time. He wondered whether he and his

team had missed some hint of the 9/11 plot as they investigated the

earlier attack on the Cole, but Soufan quickly learned that his mission

in Yemen now took on a new urgency.

There were already a number of al Qaeda operatives in custody in Yemen and, for the FBI, Soufan was the right man to question them about 9/11. He had been investigating al Qaeda for four years and knew a lot about its operatives and its ideology. He was fluent in Arabic, a Muslim himself and, at 30-years-old, he was starting to make a name for himself as one of the bureau's best interrogators of Islamic extremists.

When asked what makes a good interviewer or interrogator, Soufan replied, "Knowledge and empathy."

"You need to connect with people on a human level - regardless," he added.

"Is it hard to have empathy with someone who's just killed, or helped to kill, thousands of Americans?" Logan asked.

"Oh, absolutely," Soufan said, as he recounted an experience in which a man threatened to slaughter Soufan like a sheep.

"What did you say to him?" Logan asked.

"I kind of, like, politely put him in his place." Soufan said.

"We had a fruit next to us and there's a knife to cut the fruit. I gave him the knife," Soufan continued. "I said, 'Go ahead and do it now.' He looked at me. I said, 'I thought so. So sit down and shut your mouth and let's talk.'"

The tactic was effective because it was unexpected from an American interrogator, Soufan explained. He said al Qaeda detainees don't expect an American to offer them tea or coffee and to sit down, talk and try to develop a rapport.

"That scares them. That shakes them because they were trained that we are so evil and we torture and we kill. And that is the reason of the rage against us," Soufan said. "So they tell you a lot of stuff to piss you off and then they can say, 'See? He is evil.' So in my case, I try to deprive them from that."

"Do you think the fact that you were a Muslim gave you an advantage in some cases and in some ways?" Logan asked.

"No," Soufan said. "But the fact that maybe I understood the culture, the fact that I genuinely, as a person, have an interest in these kind of things, that probably helped me."

Soufan said he often engaged in deeply religious arguments with high-level detainees. When asked if he won those arguments, he responded, "Well, I don't know if I convinced them. But I know towards the end, I have my confession."

Just one week after 9/11, Soufan and his partner found themselves face-to-face with Osama bin Laden's bodyguard, Abu Jandal. He'd been caught and imprisoned in Yemen nearly seven months before 9/11, but now that bin Laden had attacked on U.S. soil, it was important to see if Abu Jandal could help the FBI build a case against those responsible.

Soufan described Abu Jandal's initial behavior toward American interrogators as hate-filled and dismissive, but Abu Jandal gradually began to open up.

"We were able to build a rapport with him," Soufan said.

Abu Jandal was fascinated by the history of revolutions, and Soufan said he talked with him about the American Revolution. He gave Jandal a book in Arabic about George Washington and the American Revolution.

According to Soufan, Jandal stayed up all night reading the book, "but he's practicing typical counter-interrogation techniques, where he gives you what he thinks you know so you will think he's cooperating," Soufan added.

When Abu Jandal looked at a book of photos of known al Qaeda members Soufan said that he identified very few and kept passing over a photo of Marwan al Shehhi - one of the 9/11 hijackers. Soufan knew Abu Jandal had cared for al Shehhi years ago when he was very sick and the fact that Abu Jandal was not identifying him was a signal that Abu Jandal was not being honest.

Soufan told Logan that he reminded Abu Jandal of the time he spent caring for el Shehhi in Kandahar during Ramadan in December of 1999. Soufan painted a vivid picture of Jandal "nursing (al Shehhi) and putting soup on his lips."

"I said, 'Let me make it very clear to you. You don't know how many people in the book [of photos] works for me. You don't know how many people in the book we caught and they're cooperating,'" Soufan continued. "I said, 'Why don't you look at the book again?' He identified almost everyone in the book."

Among those Abu Jandal identified as al Qaeda members were seven of the terrorists who flew planes into the World Trade Center and the Pentagon. Abu Jandal didn't know they had been involved in the 9/11 plot because he'd been in prison. Soufan said that Abu Jandal was adamant that al Qaeda and bin Laden were not behind the attack.

"I said, 'Well, I know that al Qaeda did that. Someone told me,'" Soufan said. When Abu Jandal asked who, Soufan replied "You did."

"'I said, 'Do you know who flew the planes in the World Trade Center and the Pentagon?' And I took the seven photos that he identified and put it in front of him," Soufan said. "I said, 'Those, my friend, are not my sources. Those are the people who flew the planes.' He totally collapsed."

Soufan said that when Abu Jandal realized he had given up bin Laden and al Qaeda he put his hands on face, collapsed and started shaking.

"After that, the level of cooperation was very different. We ended up spending days and days with him," Soufan said.

Abu Jandal provided nearly 100 pages of information, according to Soufan's FBI report, including intricate details about al Qaeda's training facilities, communications and weaponry. It was quite an achievement for someone who might best be described as an accidental FBI agent.

Soufan grew up in Lebanon during the country's brutal civil war. He moved with his family to the U.S. when he was 17. He was a frat boy at Mansfield University in Pennsylvania, planning a career in academia, when a college administrator suggested he apply for a job with the FBI.

Soufan said that he felt like the administrator had just told him that he should join the circus or be a racecar driver. His fraternity brothers laughed at the idea, telling Soufan that the FBI would send back his application. But Soufan remembers thinking, "We'll see about that."

In 1997, after getting a Master's degree in international relations, he joined the FBI's New York office as a rookie counterterrorism agent, and he was little more than three years on the job when he was made the case agent for the FBI's investigation of the attack on the U.S.S. Cole.

In March 2002, the U.S. captured its first high-value terrorist operative - Abu Zubaydah - after a firefight in Pakistan. Ali Soufan and his partner were called in to assist in the CIA interrogation at a secret location in Thailand. Abu Zubaydah was severely wounded, but still able to communicate. From U.S. intelligence files, Soufan had learned a lot about Abu Zubaydah and he told us he put that knowledge to good use right way.

According to Soufan, when the two first met, Zubaydah gave him the fake name of "Daoud."

Soufan asked him, "What if I call you Hani?"

The question had an impact because, according to Soufan, Hani is what Abu Zubaydah's mother called him as a child.

"Why do you think that mattered so much?" Logan asked.

"It kind of told him that 'you cannot play games with us, we know who you are,'" Soufan said.

"And what do you think is the most important information that came out of that?" Logan asked.

"The most important information is identifying Khalid Sheikh Mohammed as a mastermind of 9/11," Soufan said.

At the time, Khalid Sheikh Mohammed, or KSM, was on the FBI's most wanted list for other terrorist plots. U.S. intelligence suspected he was involved in 9/11, but the FBI didn't have any evidence of that.

Ali Soufan and his partner Steve Gaudin meant to show Abu Zubaydah a photo of someone else on the most wanted list, but they showed Abu Zubaydah a photo of KSM by mistake.

"He looks at me and he says, 'Don't play games with me, brother. Don't play games with me. You know who this guy. This is, this is Mukhtar. This is mastermind of the plane operations,'" Soufan said.

Al Qaeda called the 9/11 plot "the plane operations," Soufan explained to Logan, and Mukhtar was an alias for KSM, but at the time, Soufan did not know that.

"When he said 'Mukhtar,' it kind of, like, clicked. So, I looked at it and I said, 'Oh, Steve, you gave me the wrong photo.' And I gave it to Steve, so he will know who the mastermind of 9/11 is," Soufan said.

"You're playing it very cool, but what's going through your head really?" Logan asked.

"Holy s--t, KSM is an Al Qaeda guy, the one in 9/11?" Soufan laughed.

"It was an accident?" Logan asked.

"Totally. Totally."

Soufan says he believes Abu Zubaydah didn't mean to divulge important information and was trying to give up as little as possible.

According to Soufan, Zubaydah was well versed in counter-intelligence tactics and was a "borderline genius."

"I hear a lot of people saying he's an idiot," Soufan continued. "He's probably one of the smartest people I interrogated."

Soufan thought that he and his partner were making progress, but he says everything abruptly changed after 10 days when he was told to stop talking to Abu Zubaydah.

Soufan told Logan that the CTC, the CIA's Counterterrorism Center team, had arrived. Soufan told them that Zubaydah had been cooperating and that they had learned that KSM had masterminded 9/11.

"They said, 'Well, yeah, but there's a belief that there's a lot more information and he's not giving it up yet.'" Soufan said.

He then learned about a plan that was approved in Washington that would use harsh new techniques to "strategically diminish [Zubaydah's] ability to resist," Soufan said.

"We knew that we're going down a path that's a dangerous path," Soufan said. "We had to pull out from the interrogation, and we had to start witnessing something that was really surprising --some technique we never thought that we will see us doing."

The use of waterboarding and other tough new methods known as "enhanced interrogation techniques" - including nudity, sleep deprivation and loud music - led to a very public debate about whether the U.S. was torturing terrorism suspects.

The videotapes of those interrogations have reportedly been destroyed, and hardly anyone who participated in them has spoken publicly. Nor has enough information been made public to determine if the techniques were successful. But in April of 2002, FBI agent Ali Soufan witnessed the beginning of the use of these techniques on the U.S.'s first high-value terrorist detainee, Abu Zubaydah.

Soufan says he was making good progress with Zubaydah through traditional methods of questioning, but he was told that a CIA contractor, hired for his interrogation expertise, would be taking control. Soufan then watched on a closed circuit monitor as a very different approach was used.

"The plan at the time was to go in and tell Abu Zubaydah one question. Tell him, 'Tell me what I want to know.' And if Abu Zubaydah said, 'What do you want to know?' or ask any questions about that, the person is to walk out. And say, 'You know,' and walk out," Soufan said.

After the person who asked the question walked out, one of the harsh new techniques would be used, Soufan said.

Soufan said that it started with nudity and then escalated, "Then you have noise and you have sleep deprivation. And it goes from one stage to another, until he decided to cooperate," he said.

Logan asked Soufan why the individual who was now directing the interrogation was put in charge.

"I don't know," Soufan replied. "Supposedly, he's an expert in the field. So I ask him, 'Do you know anything about Islamic fundamentalism?' He said, 'No.' 'Have you ever interrogated anybody?' 'No.' He basically said, 'No, he knows human nature.'"

When asked how Zubaydah's reacted to the new approach, Soufan said that he stopped cooperating and the information dried up.

According to Soufan, after several days with nothing from Abu Zubaydah, he and his partner and a CIA interrogator were allowed to start talking to him once again, and they obtained information that led the CIA and the FBI to capture Jose Padilla, the American citizen accused of plotting to set off a "dirty bomb" in the U.S.

Soufan said that even though new information was now being elicited, he and his partners were once again told to stop talking to Abu Zubaydah.

"Suddenly, out of the blue, they said, 'Wait a second, you guys are gonna be out because we believe he's not cooperating anymore.' Which was really shocking for us to hear," Soufan said.

"So what did you do?" Logan asked.

"What can we do?" Soufan said. "We're watching time pass by with nobody talking to a detainee, day after day."

"No one even spoke to him?" Logan asked.

"No, they go in. They say, 'Tell me what I want to know.' He says, 'What do you want to know?' And you walk out. Period. That's it," Soufan said. "That's the whole interrogation plan, if you want to call it."

Soufan told Logan that for him the last straw was when he saw a "confinement box" at the site where Abu Zubaydah was being interrogated.

"That sounds like a coffin," Logan said.

"A confinement box," Soufan said to Logan. "I thought at the time we had the guy cooperating. So what's goin' on? I mean that box was not made overnight. There's something goin' on [that] we don't know about."

"What was the box for?" Logan asked.

"I don't know," Soufan said. "I mean, definitely it's, it's for, for Abu Zubaydah."

"But that was not the kind of technique that you were prepared to stick around for?" Logan asked.

"No," Soufan said. "I just felt that, literally, we're playing games...And I really cannot be part of this."

Soufan claims that he was not the only person that felt that way and that a CIA agent also left the location.

"Actually, he left before me," Soufan said. "And then we finally reported to headquarters that, you know, 'This-- what's happening' as I called it in the D.O.J., Department of Justice inspector general report 'borderline torture.' And FBI headquarters said, 'You know, you know we don't do that.'"

"Eventually, after that, they pulled all FBI agents from high-value detainees interrogations," he continued.

Soufan never saw Abu Zubaydah again and only occasionally saw the enhanced interrogation techniques being used after that, but he claims that when President George Bush addressed the nation in 2006, the American people were being misled.

In a speech, Bush said, "We knew that Zubaydah had more information that could save innocent lives, but he stopped talking." Bush also said that, "It became clear that he had received training on how to resist interrogation. And so the CIA used an alternative set of procedures."

"I think somebody told the president some fake information, some false information. Zubaydah did not stop talking. Introducing the techniques made him stop talking," Soufan said.

Soufan argues that terrorists like Abu Zubaydah have been trained to expect extremely brutal treatment in Middle Eastern prisons, which is one reason he believes enhanced interrogation techniques are not effective.

"If you look at them from an American perspective, you will say, 'Wow, that's torture.' But really that's like saying hello in some jail in the Middle East," Soufan said.

"This is not the torture that these guys are expecting," he continued. "So why do we start going on a path that eventually we're gonna hit a glass ceiling? And when you hit the glass ceiling, what do you do? "

"What do you do?" Logan asked.

"The detainee calls your bluff. You cannot go back and say, 'I'm gonna build a rapport.' That's why you keep repeating the glass ceiling again and again and again and again. Abu Zubaydah was waterboarded 83 times, Khalid Sheikh Mohammed 183 times. What does that tell you? Does that tell you the technique is working?"

A number of people in the CIA and the intelligence community told us that Abu Zubaydah did give up information after he was waterboarded, which they say helped save American lives and that, all moral questions aside, the enhanced interrogation program yielded significant intelligence; including information that contributed to the killing of Osama bin Laden.

"At least two former directors of the CIA, George Tenent and Michael Hayden say that enhanced interrogation techniques do work," Logan said.

"Sure, sure," Soufan said.

"They have access to more intelligence than you," Logan said.

"Absolutely," Soufan replied.

"If you don't know everything, how can you be so sure that they don't work?" Logan asked.

"Because I am privy to a lot of information that also I'm not telling you here," Soufan said.

"But is it possible for you to know all the information, everything that may or may not have been gained from these techniques?" Logan asked.

"I'm not claiming that I know everything. I know what I know," Soufan replied.

The one thing that has caused Ali Soufan more anguish than anything else is the thought that the events of 9/11 might have been prevented if, he says, the CIA had shared certain information with him and his FBI team.

While they were investigating the attack on the USS Cole in November 2000, Soufan's team learned that an al Qaeda operative had met with other terrorists in Asia and received a large sum of money. Soufan says he made three formal requests through the FBI to the CIA to see if anything was known about what this operative was up to. Each time, he says, the CIA indicated that it did not know anything.

But, Soufan says he later learned the CIA knew - eight months before 9/11 - that this same operative had met in Malaysia with two terrorism suspects who would later hijack the plane that crashed into the Pentagon. And the CIA also knew that those two suspects were heading to the U.S.

"The agency knew that these al Qaeda operatives in Southeast Asia flew to America or they have visas to come to the United States, and somebody decided, 'Let's not share the information,'" Soufan said.

"And if it had been shared with you, what then?" Logan asked.

"I try not to think about that. I try not to think about, about what could have happened. Maybe, maybe thousands of American lives will be spared, maybe," Soufan said.

The CIA told us any suggestion it purposely refused to share critical information on the 9/11 plots with FBI is "baseless" and "these allegations diminish the hard work and dedication of countless CIA officers."

Ali Soufan left the FBI six years ago, and today he runs a security consulting company based in New York. He told Lara Logan that he hasn't been to Ground Zero since the first anniversary of 9/11.

"Maybe I'm one of these people who didn't get over it," Soufan said.

"Can you tell me why?" Logan asked.

"You know, maybe part of me feels guilty. Maybe part of me feels some sort of responsibility of what happened," Soufan said.

"But you did your best. You gave your all. Why would you feel guilty?" Logan asked.

"If you want to be truthful with yourself," Soufan said, "[it's] very difficult...not to kind of like feel that...maybe I could've done something."

"Is that why it's hard for you to go to Ground Zero?" Logan asked.

"Yeah, actually, I went there once, on the first anniversary but that's it," Soufan said.

"It's hard for anyone to go there," Logan said.

"Yeah, absolutely," Soufan agreed.

"Why so hard for you, Ali?" Logan asked.

"I don't know," Soufan said, looking as if he was about to cry. "I don't know."

Ex-FBI interrogator 'gagged' over 9/11 backstory

http://www.bbc.co.uk/news/world-us-canada-14891439

By Gordon Corera & Steve Swann BBC News

A former FBI agent who worked at the heart of America's battle against al-Qaeda has told the BBC he is being prevented from telling the truth as he challenges the back story of 9/11 and what has happened since.

Mr Soufan also argues against the effectiveness of interrogation techniques used by the CIA, such as water boarding.

Ali Soufan has not appeared on camera before, but he has now decided to speak out to counter what he sees as a misleading narrative about the last 10 years.

Mr Soufan has direct, first-hand experience of some of the most heated controversies of the past decade: whether 9/11 could have been prevented and whether tactics like the water boarding of al-Qaeda suspects were effective and justified.

Born in Lebanon, Mr Soufan came to America as a teenager and joined the FBI in the 1990s. As one of the only Arabic speakers he was assigned to early investigations on al-Qaeda.

'I threw up'
When the 9/11 attacks occurred, he was in Yemen investigating the bombing of the USS Cole.

The day after the attacks, he met a CIA officer at the US embassy in Yemen. The officer passed him an envelope.

Inside was a report detailing links between people Mr Soufan had been investigating for the warship bombing and two of the hijackers - who had been living in the US for months.

Mr Soufan says that written requests for this kind of information had been made three times before without any result.

"I think it was probably the worst feeling I have ever experienced in my life," he told the BBC in an interview.

"It was a combination of frustration, anger, sadness, betrayal. The only thing I recall is I left the office, went across the hall to the bathroom and I just threw up."

He believes the material would have made a difference.

"We were looking for them overseas. They were here. People in our government knew that they were here. We were not told," he says.

The CIA denies that it failed to share the intelligence.

"Any suggestion that the CIA purposely refused to share critical lead information on the 9/11 plots with FBI is baseless," a CIA spokesperson told the BBC in a statement.

Interrogator as God
The first senior figure linked to al-Qaeda to be arrested was Abu Zubaydah. He was taken to a secret CIA site. Mr Soufan was told to go out and interrogate him.

He still cannot disclose the site's location, but the BBC believes it to be Thailand. Zubaydah was still in pain from being shot during his capture.

Mr Soufan says he was able to extract valuable intelligence with traditional interrogation techniques. This included the first identification of Khalid Sheikh Mohammed as the mastermind behind the 9/11 attacks.

But some in Washington believed Abu Zubaydah knew more. They sent out a CIA contractor to test out his theories.

Zubaydah would become the guinea pig for what the CIA called "enhanced interrogation techniques".

Abu Zubaydah, one of the first high-level Al Qaeda captures. Mr Soufan says his more orthodox interrogation of Zubaydah (pictured) gained useful information

The techniques began with nudity, sleep deprivation and loud noise.

"The idea was the detainee has to look at the interrogator as if he is his God. He is the one who determines if his life is going to be better or worse," Mr Soufan says of the CIA contractor's ideas.

Mr Soufan's objections to the techniques are primarily about their effectiveness.

"I'm not going to lose any sleep if a terrorist is nude," he says. "These things don't work.

"It's not going to work on a top-notch terrorist. My experience is you can catch way more flies with honey than vinegar."

Mr Soufan stood back as the CIA tested out its theories. He says it soon became clear that the techniques employed by the CIA contractor were not working.

The pressure was on to go further.

Mr Soufan became increasingly concerned - witnessing techniques he believed would be criminal in the US. He told the FBI he would arrest the contractor if he stayed.

The FBI told him to come home, and withdrew itself from the interrogation process. Zubaydah was then water boarded 83 times.

Former Vice-President Dick Cheney has argued these techniques were "legal, essential, justified, successful".

Mr Soufan challenges this view.

"Everything the proponents of enhanced interrogation techniques claim was obtained because of enhanced interrogation techniques and water boarding on Abu Zubaydah, we got when we were there on the ground before even enhanced interrogations existed," he says.

In response to his story, a US counter-terrorism official told the BBC that the CIA and FBI had different roles.

"Mr Soufan and his colleague were part of the initial questioning, when Abu Zubaydah was hospitalised, and Mr Soufan was trying to build a rapport," said the official.

"Later when Abu Zubaydah recovered, he stopped any pretence of co-operation.

"The CIA claim that after the FBI pulled its officers from the debriefings, and the decision was made to focus the debriefings on collection of intelligence and on pending attacks, he became very co-operative. "

Major redactions
Mr Soufan - who left the FBI in 2005 - believes that his attempts to challenge the narrative of 9/11 and what came afterwards is being deliberately blocked by the authorities.

His book, The Black Banners, is published in the US and UK on Monday.

The FBI did not object to the manuscript, but the CIA demanded major redactions.

In some cases, entire pages of the book have been redacted, including parts of Mr Soufan's testimony before the US Senate.

In certain passages, the words "I" and "me" have been redacted where Mr Soufan is relating his own eyewitness account of events.

"The suggestion that the Central Intelligence Agency has requested redactions on this publication because it doesn't like the content is ridiculous," a CIA spokesperson told the BBC.

"The CIA's pre-publication review process looks solely at the issue of whether information is classified... just because something is in the public domain doesn't mean it's been officially released or declassified."

Mr Soufan believes that the process has not been about what is or is not classified.

"People over there are redacting narrative; they are not redacting national security information," he told the BBC.

"They are trying to stop me and others from telling the world what really happened."

FIND OUT MORE: Watch Gordon Corera's full report on Newsnight on Monday 12 September at 22:35 BST on BBC Two