"I believe that the (Uighur) people were trying to get back their country from China and I don't believe Osama bin Laden or the Taliban were financially providing for the camp," he said at the tribunal.
Parhat also said he wasn't an enemy of the United States, and that he and other Uighurs had left China because they were being persecuted.
"We have never been against the United States," he said. "I think that the United States understands the (Uighur) people."
The military has concluded at various times that Parhat should be released, Pinney said.
The tribunal found in 2005 that there was no evidence that Parhat was a member of the East Turkistan Islamic Movement. However, it concluded that because he'd attended the camp, he still could be held as an enemy combatant.
A review board later cleared him for release. Defense attorneys don't know the exact date of the decision, but were informed in February 2007. By then, Parhat's lawyers were waiting for the courts to rule on a challenge to his detention and to his enemy-combatant status.
Declassified documents turned over to Parhat's lawyers showed that government officials had recommended releasing him as early as 2003.
Pinney said he thought that U.S. officials hadn't released him in part to avoid harming diplomatic relations with China. Parhat's lawyers have demanded that the military find another country that's willing to accept him, citing Parhat's fear that he'll be tortured if he's returned to China.
Earlier this month, the Supreme Court ruled 5-4 that Guantánamo Bay detainees can challenge their extended imprisonment in federal court, and struck down the circuit court review as an alternative.
The ruling in Boumediene v. Bush was the latest in a string of judicial defeats for the Bush administration. It marked the third time in four years that the Supreme Court has repudiated the administration's efforts to exclude foreign prisoners from traditional legal protections.
The Miami Herald's Carol Rosenberg contributed to this report from Miami.