Just months after U.S. Army troops whisked a German man from Pakistan to the military prison at Guantanamo Bay, Cuba, in 2002, his American captors concluded that he was not a terrorist.

"USA considers Murat Kurnaz's innocence to be proven," a German intelligence officer wrote that year in a memo to his colleagues. "He is to be released in approximately six to eight weeks."

Yet the 19-year-old student was not freed. Instead, over the next four years, two U.S. military tribunals that were responsible for determining whether Guantanamo Bay detainees were enemy fighters declared him a dangerous al-Qaedaally who should remain in prison.

The disparity between the tribunal's judgments and the intelligence community's consensus view that Kurnaz is innocent is detailed in newly released military and court documents that track his fate. His attorneys, who sued the Pentagon to gain access to the documents, say that they reflect policies that result in mistreatment of the hundreds of foreigners who have been locked up for years at the controversial prison.

The U.S. Supreme Court intends to weigh the legitimacy of the military tribunals at a hearing Wednesday morning. Lawyers for Kurnaz and other detainees plan to argue that the panels violate the U.S. Constitution and international law. They say that the proceedings have not provided Guantanamo Bay detainees with a fair and impartial hearing.