WASHINGTON — U.S. military intelligence assessing the threat of nearly 800 men held at Guantanamo in many cases used information from a small group of captives whose accounts now appear to be questionable, according to a McClatchy Newspapers analysis of a trove of secret documents from the facility made public by WikiLeaks.

The allegations and observations of just eight detainees were used to help build cases against some 255 men at Guantanamo – roughly a third of all who passed through the prison. Yet the testimony of some of the eight was later questioned by Guantanamo analysts themselves, and the others were subjected to interrogation tactics that defense attorneys say amounted to torture and compromised the veracity of their information.

Concerns about the quality of the “facts” from the eight men goes to the heart of Guantanamo’s “mosaic” approach of piecing together detainees’ involvement with insurgent or terrorist groups that usually did not depend on one slam-dunk piece of evidence. Rather, intelligence analysts combined an array of details such as the items in detainees’ pants pockets at capture and whether they had confessed to interrogators – American or otherwise.

More than two-thirds of the men and boys at Guantanamo were not captured by U.S. forces. So analysts were often left to weave together the stories told by detainees, the context of where and how they were initially scooped up, the information passed on by interrogators at other U.S. detention sites and, crucially, the testimony of fellow detainees at Guantanamo.

At Guantanamo, the captives were aware that some prisoners were providing a pipeline of information to interrogators – either to justify their continued detention or for use in potential prosecutions before military commissions.

“I heard there was another detainee talking about me,” former Briton detainee Feroz Abassi said in a recent interview with McClatchy Newspapers. “I thought, let them talk. They’re only going to corroborate my story.”

After being held at Guantanamo for more than three years, Abassi was released in a diplomatic deal in January 2005 at age 25. He now works as a caseworker at the London-based detainee activist group Cageprisoners.

Abassi said it later became apparent that some informants were “straying away from the truth, trying to save themselves. They crack and they think it helps them to point fingers. But they only dig a hole for themselves.”

That appears to have been the case for Mohammed Basardah, a self-described one-time jihadist whose information was used in assessments for at least 131 detainees. In some instances, he accused fellow detainees of training at militant camps or taking part in the fighting in Afghanistan against the U.S. and its allies in late 2001.

Other times, intelligence analysts simply inserted a sliver of a quote from Basardah about the guilt of everyone caught at Tora Bora – the rugged mountain region where Osama bin Laden and members of his inner circle fled following the Sept. 11, 2001 attacks – as a sort of blanket truism.

The Yemeni’s testimony was included despite worries highlighted in a 2008 Guantanamo intelligence assessment that his “firsthand knowledge in reporting remains in question” and a remark that many of fellow prison camp captives seemed “willing to reveal self-incriminating information to him.”

At the Pentagon, Army Lt. Col. Tanya Bradsher said the military would not be commenting on McClatchy Newspapers’ findings because “the documents disclosed by Wikileaks are the stolen property of the U.S. government. The documents are classified and do not become declassified due to an unauthorized disclosure.”

Among the other informants, who were used in the assessments to both make direct allegations against detainees and explain more general issues such as the relationship between various militant groups:

A Syrian detainee known as Abdul Rahim Razak al Janko, whose own file said that “there are so many variations and deviations in his reporting, as a result of detainee trying to please his interrogators, that it is difficult to determine what is factual.” He was quoted or cited in records for 20 detainees.

Muhammad al Qahtani, a Saudi man whose interrogations reportedly included 20-hour sessions and being led around by a leash, appeared as a source in at least 31 cases. A Guantanamo analyst note about Qahtani acknowledged that “starting in winter 2002/2003, (Qahtani) began retracting statements,” though it argued that based on corroborating information “it is believed that (his) initial admissions were the truth.”

At the Center for Constitutional Rights in New York, the firm that has championed Qahtani’s unlawful detention lawsuit, senior attorney Shane Kadidal said that “the information that was given in the first place (by Qahtani) was not reliable.” As a condition of his security clearance, Kadidal said, he couldn’t discuss the specifics of the WikiLeaks documents.

Ibn al Shaykh al Libi, a Libyan, told CIA de-briefers in 2004 that he had earlier exaggerated his status in al Qaida because he thought that’s what American interrogators wanted to hear. He also said he fabricated links between Iraq and al-Qaida to avoid mistreatment or torture by Egyptian interrogators. Information from al Libi was cited in at least 38 of the Guantanamo files.

On Sunday, the Department of Defense released a statement saying the Obama administration’s current Guantanamo Review Task Force has in some cases come to the same conclusions as the 2002-2009 assessments, and “in other instances the review task force came to different conclusions, based on updated or other available information.”

Any lingering doubts about the eight men and the quality of their statements were rarely listed when their information appeared in the case files of other detainees. Guantanamo officials were so pleased with Basardah’s work, for example, that his identifying a fellow detainee was used as an example in a guide to “threat indicators.”

But in a 2009 opinion ordering the Pentagon to release Guantanamo detainee Saeed Mohammed Saleh Hatim, U.S. District Judge Ricardo Urbina pointed out that Basardah’s allegations about Hatim were collected several years after Guantanamo interrogators knew there were problems.

While the government maintained that Basardah provided interrogators with “accurate, reliable information,” Urbina said that Basardah had been flagged as early as May 2002 by a Guantanamo interrogator who did not recommend using him for further intelligence gathering “due in part to mental and emotional problems (and) limited knowledgeability.”