Although Abu Zubaida was not a member of al-Qaeda and had limited relations with bin Laden, he was a font of information on the membership of the terrorist group because of his long-standing ties with Mohammed and North African jihadists, according to former intelligence and law-enforcement officials who have read his files. Abu Zubaida’s attorneys maintain that he had no connection with al-Qaeda.

“You’ve got it all wrong,” the detainee told one interrogator in May 2002, according to a former intelligence official with access to sensitive records. Abu Zubaida said that al-Qaeda had been surprised at the devastating efficacy of the Sept. 11 attacks and that any plans for future attacks were mere aspirations…

Finally, he was waterboarded.

Abu Zubaida told the Red Cross that a black cloth was placed over his face and that interrogators used a plastic bottle to pour water on the fabric, creating the sensation that he was drowning.

The former U.S. official said that waterboarding forced Abu Zubaida to reveal information that led to the Sept. 11, 2002, capture of Ramzi Binalshibh, the key liaison between the Hamburg cell led by Sept. 11 hijacker Mohammed Atta and al-Qaeda’s leadership in Afghanistan.

But others contend that Binalshibh’s arrest was the result of several pieces of intelligence, including the successful interrogation by the FBI of a suspect held at Bagram air base in Afghanistan who had been in contact via satellite phone with Binalshibh, as well as information gleaned from an interview Binalshibh gave to the television network al-Jazeera.

Abu Zubaida was waterboarded 83 times over four or five days, and Mitchell and Jessen concluded that the prisoner was broken, the former U.S. official said. “They became convinced that he was cooperating. There was unanimity within the team.”