Washington, Aug 18 (DPA): The US Central Intelligence Agency has videotapes made at a secret prison in Morocco showing the interrogation of a conspirator in the terrorist attacks of September 11, 2001, CNN reported Tuesday.

The tapes were reportedly found three years ago under a desk at the CIA's headquarters in Langley, Virginia, and may offer insights into the controversial role that some foreign countries played during former president George W Bush's war against terrorism.

The tapes show Ramzi Bin al-Shibh, who has admitted to helping plot the Sep 11 attacks on New York and Washington, CNN reported, citing a "knowledgeable US source". Bin al-Shibh is not being subjected to torture, instead he is shown being interrogated behind a desk.

It would mark the only video evidence remaining of the CIA's secret overseas prisons system, which was reportedly used for interrogations of terrorist suspects that human rights groups claim amount to torture.

The CIA had reportedly destroyed other videotapes of its interrogations at the so-called black site prisons, which were used in the first years of Bush's administration.

"Today's report is a stark reminder of how much information the government is still withholding about the Bush administration's interrogation policies," said Alexander Abdo of the American Civil Liberties Union, a civil rights group.

Bin al-Shibh and four other conspirators, including alleged mastermind Khalid Sheikh Mohammed, are facing the death penalty for their role in the Sep 11 attacks. The case has been delayed amid a divisive debate over where to hold the trial.