A federal judge in Washington had ordered the release of Mohammed al-Adahi, saying the government did not have enough evidence to hold him. But a federal appeals court unanimously reversed, pointing to allegations al-Adahi had met several times with Osama bin Laden and had attended an al-Qaida training camp.
Al-Adahi was arrested in Pakistan in 2001.
In denying review of his case, the high court said Justice Elena Kagan took no part in the decision. Kagan was U.S. solicitor general before joining the Supreme Court this term.