Anyone who had the time to read the summary of the 6,700-page report by Senate investigators on the federal government’s program of torturing detainees captured after the Sept. 11 attacks knew, or at least suspected, that there was more to the sickening story.

This week, a Reuters report added to those suspicions with newly declassified statements from Majid Khan, a high-value prisoner who had been affiliated with Al Qaeda, was captured in 2003 and has been held at Guantánamo Bay since 2006.

Over more than seven years of conversations at Guantánamo with his lawyers from the Center for Constitutional Rights, Mr. Khan described even more torture and abuse than is contained in the Senate report. Although the details of his account, as documented in notes by his lawyers, could not be independently confirmed, they corroborate many of the findings of the report.

Soon after his capture, Mr. Khan said, interrogators waterboarded him twice, a contention that contradicts the Central Intelligence Agency’s claim that it had already named all detainees who were subjected to that practice. (The C.I.A. has denied that Mr. Khan was waterboarded.) As he was moved among a series of C.I.A.-operated “black sites” over the following months, Mr. Khan told his lawyers, the torture continued. He was beaten repeatedly. He was hung naked from a wooden beam for three days, shackled and starved. He was taken down once during that time to be submerged in an ice bath. Interrogators pushed his head under the water until he thought he would drown. He received what he called “violent enemas,” and was anally assaulted in a process the interrogators called “rectal feeding.”