“Dear Mr. Warner: I like this new song Gangnham-style,” Muhammad Rahim al-Afghani wrote in imperfect English to his lawyer in November 2012. “I want to do the dance for you but canot because of my shakles. please ask to have this changed.”

Rahim is one of 16 high-value detainees still held by the U.S. at the Guantánamo Bay prison, with no current prospect of being released or being put on trial.

A citizen of Afghanistan, he was seized in Pakistan on June 25, 2007, held by the CIA and then sent to Guantánamo on March 14, 2008 — the last known prisoner to arrive at the base and, according the Senate torture report released on Tuesday, the last to enter the CIA’s detention and interrogation program.

The U.S. military describes Rahim as a high-ranking member of Al-Qaeda and a close associate of Osama bin Laden.

In 2008 then–CIA Director Michael Hayden reportedly said Rahim was being held because of “his past and the continuing threat he presented to American interests.”

But Rahim has never been charged with any crime. When WikiLeaks released its trove of documents about prisoners in Guantánamo, there were none about him.

He is, however, mentioned in the summary of the Senate Intelligence Committee’s torture report released Tuesday. On page 164, for example, the report notes that Hayden sent a letter requesting that President George W. Bush issue an executive order interpreting the Geneva Conventions in a manner that would allow Rahim to be questioned using the CIA’s “enhanced interrogation” techniques. It also notes that four CIA interrogators began applying those techniques to Rahim on July 21, 2007.