In early 2004, a group of interrogators dubbed "the contractors" spent day after day inside a special wing in the Navy's brig in Hanahan. Their goal: Squeeze information out of a suspected terrorist from Qatar named Ali Saleh al-Marri.

They didn't get anywhere; Al-Marri spent much of his time praying. What happened next remains unclear because of the brig's post-9/11 shroud of secrecy, a shroud that some believe covers clues that may explain three deaths in Guantanamo Bay, Cuba.

Al-Marri later told his attorneys that interrogators stuffed a sock in his mouth and taped his lips shut with duct tape. Al-Marri said he loosened the tape; the interrogators taped it more tightly. When he started to choke, the interrogators ripped off the tape. Al-Marri's attorney in Charleston, Andy Savage, calls this technique "dryboarding."

The military denies that al-Marri was tortured, and Ali Soufan, a former interrogator with the FBI, told The Post and Courier that dryboarding wasn't a standard "enhanced interrogation technique."

Al-Marri's description, however, recently caught the eye of Almerindo Ojeda, director of the Center for the Study of Human Rights in the Americas, a group based at the University of California at Davis.

Ojeda said Al-Marri's story reminded him of facts related to three deaths of detainees in Guantanamo in 2006. All three died with fabrics in their mouths.

The military says these deaths were suicides - and possibly a synchronized display of defiance toward the United States. But human rights groups question the military's investigation into the deaths and say the three may have been killed.

"The dryboarding of Mr. al-Marri raises an unavoidable question," Ojeda says in an article. "Did the three individuals found hanging in Guant namo die from dryboarding rather than by hanging?"

A decade after the Sept. 11, these and other questions about the treatment of detainees in the brig and Guantanamo continue to spur debate over how best to prosecute terrorism suspects and prevent attacks from happening in the future.

They also come amid the Obama administration's evolving plans to determine the fate of detainees in Guantanamo, Iraq and other bases, plans that reportedly have spawned new interest in reopening the brig or another facility on U.S. soil as a prison for terrorism suspects.

An interrogator talks

Few people know more about terrorism interrogations than Soufan, who left the FBI in 2005 and now heads the Soufan Group, a security consulting company. Fluent in Arabic, Soufan was lead investigator into the bombing of the USS Cole. In his new book, "The Black Banners," Soufan describes how he and his team may have been able to prevent the Sept. 11 attacks, had he been given a CIA file in a timely manner.

Soufan used traditional FBI techniques to get useful intelligence from al-Qaida leaders. This typically involved painstaking efforts by agents to establish rapport. He says that over time, the Bush administration pushed the CIA to use more aggressive techniques, including waterboarding, moves that backfired and caused some subjects to stop cooperating.

In 2009, Soufan testified behind a black curtain before a Senate committee, saying the Bush administration's enhanced interrogation techniques didn't work.

His book, however, doesn't specifically mention al-Marri's interrogations at the brig, a significant gap considering how much time he spent there trying to get al-Marri to talk.

Handwritten logs from the brig obtained by Savage show that Soufan visited the brig more than two dozen times in late 2003 and early 2004. He and other interrogators sometimes spent much of the day there, the logs show. (The once-secret logs were declassified as part of al-Marri's criminal case.) Brig staff sometimes called the group "the contractors."

In a phone interview, Soufan said he couldn't discuss the al-Marri interrogations because of intelligence classification rules.

Asked if, generally speaking, whether taping someone's mouth shut was part of the federal interrogation repertoire, Soufan said he wasn't "aware of that thing called dryboarding, period. It's not part of enhanced interrogation techniques. I never witnessed it anywhere, in Guantanamo or anywhere else."

Questions about deaths

The deaths of the three detainees in Guantanamo in 2006 have long been a source of controversy.

Military officials said the three hung themselves with nooses made from sheets and clothes. All three were found with fabrics stuffed in their mouths; one had a sock down his throat. After the bodies were discovered, then-Rear Adm. Harry B. Harris Jr. said what happened was "not an act of desperation, but an act of asymmetrical warfare waged against us."

Human rights activists and journalists immediately challenged the military's account. Guards were supposed to monitor the inmates every 10 minutes, but the detainees died two hours before their bodies were discovered. Critics also questioned how people could stuff fabrics down their throats, tie their own hands, and in one case, feet, and then hang themselves.

In 2009, the Seton Hall School of Law Center for Policy and Research examined 1,700 heavily redacted documents related to the deaths and found the military's investigation "deeply flawed." A Harper's magazine article by Scott Horton asserted that the three detainees may have died at a secret site in Guantanamo dubbed "Camp No," and that their bodies were moved back to their cells where they were discovered.

Last month, Ojeda, director of the UC-Davis center's Guantanamo Testimonials Project, came across a story in The Post and Courier that referenced al-Marri's treatment in the Charleston brig. In an article, he said the controlled suffocation techniques applied to al-Marri could possibly shed light on the Guantanamo deaths.

"It is clear that dryboarding can dispose, single-handedly, of all the questions we have raised thus far," Ojeda wrote.

Duct tape used

Morris Davis, former chief prosecutor for the military commissions in Guantanamo Bay, doesn't think the triple-homicide scenario is plausible.

Davis, a retired Air Force colonel, now teaches at Howard University School of Law and is executive director for the Crimes of War Education Project. Davis has been an outspoken critic of torture; he resigned as chief prosecutor in 2007 because he was concerned that interrogators were using torture to gain evidence.

He said the three who died had no good intelligence, so interrogators would have had no reason to talk to them, much less torture them. "So there's no motive." He said that removing them from that particular cell block would have been a highly visible activity ("You couldn't walk down that hallway without a bunch of people screaming at you."); and moving the detainees would have required many different actors, making a conspiracy even less likely. "I'm firmly convinced they were suicides."

Davis did say that military-grade duct tape was used to control detainees when their behavior got out of hand. Sometimes it was placed over their mouths when they screamed at guards. "But I wouldn't say it was a common technique," he said, adding that he didn't think the use of the tape "constituted torture in itself," unless it was left on for an extended period of time making it difficult for detainees to breathe. He wasn't aware of any cases in which that happened, and like Soufan, he had not heard of the term dryboarding.

Given his isolation, could al-Marri have thought being taped was torture when it was something else? For instance, at one point, al-Marri thought he was being poisoned with gas. But the odor was merely from the nearby KapStone (former MeadWestvaco) plant.

But Savage said al-Marri described something akin to torture. "The effect was the same as waterboarding" with al-Marri "believing they were suffocating him, all the while pointing to photos of his children and wife and issuing threats about what they would do to them." Savage said that al-Marri also acknowledged that he was uncooperative and chanting prayers during the interrogations. Videos were taken of the interrogations, but the Defense Department has refused to release them.

Guilty plea

Al-Marri finally did talk.

After his election, President Barack Obama moved al-Marri's case back into the U.S. justice system. The FBI had strong evidence in 2002 -- before he was declared an enemy combatant and moved to the brig -- that he had links to Khalid Sheikh Mohammed, mastermind of the Sept. 11 attacks.

Al-Marri agreed to plead guilty in 2009 to conspiracy charges and is now serving an eight-year sentence. It was then, Savage said, that he gave information to federal investigators.

Soufan said the criminal justice system is well-equipped to handle terrorism cases, such as al-Marri's. But the creation of separate detention facilities for terrorism detainees "created that feeling that there's something else going over there," he said. "It's one of these things that you do and you just shoot yourself in the foot with huge public relations nightmare for the U.S. government. It's not worth it."