WASHINGTON, Dec. 8 — The first of the so-called high-value Guantánamo detainees to have seen a lawyer claims he was subjected to “state-sanctioned torture” while in secret C.I.A. prisons, and he has asked for a court order barring the government from destroying evidence of his treatment.

Lawyers for the detainee, Majid Khan, a former Baltimore resident, released documents in his case on Friday. They claim he “was subjected to an aggressive C.I.A. detention and interrogation program notable for its elaborate planning and ruthless application of torture” to numerous detainees.

The documents also suggest that Mr. Khan, 27, and other high-value detainees are now being held in a previously undisclosed area of the Guantánamo prison in Cuba he called Camp 7.