WASHINGTON Attorney General Michael B. Mukasey said Wednesday that the Justice Department had elevated its inquiry into the destruction of Central Intelligence Agency interrogation videotapes into a formal criminal investigation to be headed by an outside prosecutor.
The announcement is the first sign that investigators believe C.I.A. officers, possibly along with other government officials, may have committed criminal acts in their handling of the tapes, which depicted the interrogations in 2002 of two Al Qaeda operatives and were destroyed in 2005.
The tapes were never provided to the Sept. 11 commission or to the courts, and the question of whether to destroy them was for nearly three years the subject of deliberations at the highest levels of the Bush administration.
Mr. Mukasey assigned an outside investigator, a federal prosecutor from Connecticut, to lead the criminal inquiry in tandem with the Federal Bureau of Investigation. The prosecutor, John H. Durham, is likely empanel a grand jury to hear testimony to determine whether there is enough evidence to bring criminal charges, which could include obstruction of justice.
As an outside prosecutor, Mr. Durham oversaw an investigation into the F.B.I.’s use of mob informants in Boston. He has been lead prosecutor in several successful corruption cases in Connecticut.
The announcement came after a joint inquiry by the Justice Department and the C.I.A.’s inspector general determined that the destruction of the tapes warranted a full criminal investigation. In an announcement on Wednesday, John Helgerson, the inspector general, said he would recuse himself from the investigation to avoid the appearance of a conflict of interest.
Mr. Helgerson’s office had reviewed the videotapes, documenting the interrogation of Abu Zubaydah and Abd al-Rahim al-Nashiri, as part of an investigation into the agency ‘s secret detention and interrogation program.
The tapes are thought to portray the use of the technique known as waterboarding, which simulates drowning and which has widely been condemned as torture.
Mr. Helgerson completed his investigation into the program in early 2004.
The newly announced investigation is likely to provide fodder on the presidential campaign trail for critics of administration policies on the detention and interrogation of terror suspects.
The fate of the tapes had been debated by at least four top White House lawyers, according to current and former administration and intelligence officials.
Those officials said the White House lawyers included Alberto R. Gonzales, then the White House counsel and later the attorney general. Mr. Gonzales resigned under pressure on Aug. 27, and Mr. Mukasey succeeded him.
Administration critics blamed Mr. Gonzales for carving out positions on detention and interrogation they deemed too permissive. So the actions of Mr. Mukasey, who as a federal judge in New York built a reputation as tough on terrorism, are being closely watched.
It remains unclear how various administration officials argued on the matter of the tapes, though one former senior intelligence official familiar with the matter said there had been “vigorous sentiment” among some top White House officials that the tapes should be destroyed.
White House spokesmen have been scrupulous about not commenting on the matter, citing investigations already begun by the C.I.A. inspector general and Congress.
The C.I.A. said that it would “cooperate fully with this investigation, as it has with others into this matter.”
The House Intelligence Committee has ordered Jose A. Rodriguez Jr., the former C.I.A. official who has been described by intelligence officials as having authorized the destruction of the tapes, to appear at a hearing on Jan. 16.
Brian Knowlton contributed reporting.