"There is a basis for initiating a criminal investigation of this matter, and I have taken steps to begin that investigation," Attorney General Michael Mukasey said in a statement issued by the department.
The CIA last month disclosed that it had destroyed in 2005 hundreds of hours of tapes from the interrogations of two al Qaeda suspects, prompting an outcry from Democrats, human rights activists and some legal experts.
The interrogations, which took place in 2002, were believed to have included a form of simulated drowning known as waterboarding, condemned internationally as torture.
President George W. Bush has said the United States does not torture but has declined to be specific about interrogation methods.
The Justice Department and the CIA's inspector general last month launched an initial inquiry into the tapes. Congress is also investigating the tapes' destruction.
The CIA said it would "cooperate fully with this investigation, as it has with others into this matter."
But the agency's inspector general, John Helgerson, said he would step aside from the full investigation.
Helgerson said the inspector general's office had reviewed the tapes "some years ago" as part of a review into agency interrogations and that he had helped prepare a report on the issue, so it would be inappropriate to be involved in the probe.
Mukasey said he had asked a federal prosecutor from Connecticut, John Durham, to lead the probe.
© 2007 Reuters