The CIA destroyed 92 videotapes showing interrogation of terror suspects using water-boarding and other "enhanced techniques" that critics say amount to torture -- a far greater number than previously known -- according to court documents.

The American Civil Liberties Union said the news showed the CIA had deliberately defied a 2004 court order and sought to cover up the illegal use of torture against a handful of so-called high-value detainees, including the self-confessed architect of the Sept. 11, 2001, attacks, Khalid Sheik Mohammed.

A court filing in a Freedom of Information Act case brought by the ACLU against the CIA said that as a criminal inquiry into the tapes' destruction wound down, the agency "was now gathering information and records responsive to the court's order."

It said the agency on Friday would produce a schedule of when additional information would become available but warned that much data covered by the case -- such as a list of CIA personnel who had seen the tapes -- might be classified or otherwise protected from disclosure under the Freedom of Information Act. In the meantime, the filing said, the agency could reveal that 92 tapes had been destroyed.

"Clearly this is a coverup of illegal activity … in violation of a court order," ACLU attorney Amrit Singh told United Press International. "The sheer number (of tapes destroyed) demonstrates that this was a deliberate and systematic attempt to hide these unlawful activities from the American people."

White House spokesman Robert Gibbs said he had not discussed the matter with President Barack Obama but called it a "sad" development, repeating the administration's pledge to "give the people that work in the CIA the tools they need to keep us safe, but do so in a way that also protects our values."

The existence of the tapes -- and the fact that they had been destroyed in 2005 -- came to light in December 2007. Michael Hayden, CIA director at the time, said the tapes were made "as an additional, internal check on the (interrogation) program in its early stages."

CIA officials, he added in a note to agency staff released to the press, decided to destroy them "only after it was determined they were no longer of intelligence value and not relevant to any internal, legislative or judicial inquiries."

The following month, the ACLU -- which had a longstanding Freedom of Information Act case against the CIA regarding records of its detention and interrogation practices -- filed a motion urging that the agency be held in contempt of court. ACLU lawyers argued that, despite a 2004 court order to identify or produce all records related to its interrogation of terror suspects, the CIA not only failed to do so but also destroyed some of the records.

The FOIA case aside, federal law provides for the retention of all agency records, and the unlawful destruction of them is a felony punishable by a fine of up to $2,000 and a prison sentence of up to three years. However, the law does include exceptions for records that are deemed "a continuing menace to human health or life or to property," and for records held overseas -- as the videotapes reportedly were -- "during a state of war … or when hostile action by a foreign power appears imminent."

"The problem with any FOIA case against the agency is that there are exemptions you can drive a truck through -- even one full of videotapes," said a former senior U.S. national security lawyer. "There are also exemptions to the federal records law where lives might be at stake or where the nation is at war, some of which might arguably apply here."

But the revelations in December 2007 about the tapes' destruction also set in motion a criminal inquiry. On Jan. 2, 2008, Attorney General Michael Mukasey appointed a career prosecutor, John Durham, to head an investigation into the tapes' destruction, although he did not say what laws might have been broken.

It is this inquiry that now appears to be winding down. In three successive declarations last year, Durham asked the court to stay consideration of the contempt issue while his inquiry continued to review documents and interview witnesses. The last of these declarations stated that, despite the difficulties involved in conducting an inquiry involving such a large volume of highly classified materials, he expected to have finished interviews by Feb. 28.

Observers cautioned that the end of the investigation did not necessarily mean that any criminal charges would be brought.

"The federal statutes covering obstruction of justice are extremely broad, and it is very risky to destroy any record that could be part of a future criminal case," the former senior national lawyer said. "But at the end of the day, it would really be a question of intent."

"CIA has certainly cooperated with the Department of Justice investigation," said agency spokesman Paul Gimigliano. "If anyone thinks it's agency policy to impede the enforcement of American law, they simply don't know the facts."