The CIA in 2005 destroyed at least two videotapes of the interrogation of two Al-Qaeda operatives, amid increasing questions about the agency's detention program, The New York Times reported on Friday.
Citing current and former government officials, the report said the tapes "showed agency operatives in 2002 subjecting terrorism suspects -- including Abu Zubaydah, the first detainee in CIA custody -- to severe interrogation techniques."
CIA chief Gen. Michael Hayden on Thursday told colleagues "the decision to destroy the tapes was made 'within the CIA' and that they were destroyed to protect the safety of undercover officers and because they no longer had intelligence value," the report said.
Yet the "destruction of the tapes raises questions about whether agency officials withheld information from Congress, the courts and the September 11 commission about aspects of the program," it added.
Hayden, in a letter to employees obtained by CNN television, said of the tapes that "beyond their lack of intelligence value -- as the interrogation sessions had already been exhaustively detailed in written channels -- and the absence of any legal or internal reason to keep them, the tapes posed a serious security risk."
"Were they ever to leak, they would permit identification of your CIA colleagues who had served in the program, exposing them and their families to retaliation from Al-Qaeda and its sympathizers," it added.
The United States, following the September 11 terror strikes, launched a program allowing intelligence services to detain and question terror suspects, including questioning techniques that are secret, while in the military these are clearly spelled out.
The report came on the heels of a decision by lawmakers that all US officials including intelligence officials should follow the same rules as the military and renounce all forms of torture.
The final version of the intelligence budget for 2008, taken up Thursday by the House and Senate, says US military rules on interrogations also should apply to US civilian officials. The text still must be approved by both houses.
It was not certain that the measure, welcomed by the ACLU civil rights organisation, would ever take effect. President George W. Bush could veto it.
The ACLU meanwhile voiced concern at the CIA's action on the videotapes.
"The destruction of these tapes appears to be part of an extensive, long-term pattern of misusing executive authority to insulate individuals from criminal prosecution for torture and abuse," the American Civil Liberties Union said in a statement.
Senate Intelligence Committee chairman John Rockefeller said in a statement that "our committee must review the full history and chronology of the tapes, how they were used and the reasons for destroying them, and any communication about them that was provided to the courts and Congress.
"While we were provided with very limited information about the existence of the tapes, we were not consulted on their usage nor the decision to destroy the tapes. And, we did not learn until much later, November 2006 -- two months after the full committee was briefed on the program -- that the tapes had in fact been destroyed in 2005."
In October, the Times reported that the CIA was investigating the work of the spy agency's own internal inspector general, whose aggressive inquiries into torture allegations have ruffled agency staff.
Hayden ordered the investigation into the work of the agency watchdog, the Times said at the time, citing current and former government officials.
The review was to see whether the inspector general, John Helgerson, has embarked on a crusade against agency officials working in its detention program, which has been accused of using torture to interrogate terror suspects.
The Times has said that Helgerson's office in an early 2004 report warned that some CIA-approved interrogation procedures appeared to violate the international Convention Against Torture.
Helgerson is also near to finishing several investigations into CIA detentions and interrogation and its rendition program, which involves detaining suspects and holding them in other countries, or turning them over to officials in other countries, the Times has said.
The CIA inspector general's office also earlier reported on the agency's failures before the September 11, 2001 attacks, a report whose conclusions angered many inside the agency.