The US department of justice will launch a criminal investigation into the destruction of videotapes showing the interrogation of terrorism suspects, the US attorney-general has said.
Michael Mukasey on Wednesday appointed John Durham, a federal prosecutor, to oversee the investigation.
Mukasey said: "The department's national security division has recommended, and I have concluded, that there is a basis for initiating a criminal investigation of this matter, and I have taken steps to begin that investigation."
Last month, the CIA had acknowledged that it destroyed videos of officers using allegedly tough interrogation methods while questioning two "terror" suspects.
The acknowledgment resulted in a congressional inquiry and a preliminary investigation by the department.
Waterboarding
The interrogations, which took place in 2002, were believed to have included waterboarding, a form of simulated drowning condemned internationally as torture.
"The CIA will of course cooperate fully with this investigation as it has with the others into this matter," Mark Mansfield, the intelligence agency's spokesman said.
Congressional investigators have begun reviewing CIA documents at the agency's headquarters.
The house intelligence committee of the US house of representatives ordered Jose Rodriguez, the former CIA official who directed the tapes be destroyed, to appear at a hearing on January 16.
George Bush, the US president, has denied claims of torture, but has declined to be specific about interrogation methods.