U.S. Justice Department officials say the inquiry is intended to focus on the tapes’ destruction, but investigators can pursue any evidence of other illegal acts.

The probe could also reach into the White House, where senior aides reportedly debated whether the tapes should be destroyed.

Opponents and defenders of the CIA’s interrogation techniques, including a form of simulated drowning known as waterboarding, say the investigation should give a full airing to what constitutes torture and whether the United States has engaged in it.

“This could be a springboard,” said Jeffrey Addicott, a former U.S Army Special Forces legal adviser who heads the Center for Terrorism Law at St. Mary’s University law school in Texas.

There is little U.S. court precedent on torture, he said. President George W. Bush has said the United States does not torture but has declined to be specific about interrogation methods.

“There are some questions that need to be answered, particularly these serious allegations about the United States engaging in torture. I think it’s in our best interests to find out what occurred and to put this to rest as soon as possible,” Addicott said.

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 CIA says it acted lawfully, but the probe will consider whether the agency broke the law by flouting court orders and investigators’ requests that it provide evidence in various terrorism cases.

The interrogations took place in 2002 and were believed to have included waterboarding, condemned internationally as torture.

U.S. Attorney General Michael Mukasey, who ordered the probe, declined to say in his Senate confirmation hearings last year whether he considered waterboarding illegal torture.

‘ON A LEASH’

American Civil Liberties Union legal counsel Christopher Anders said of the investigation, “It should not be enough to simply look at the tapes and whether they were destroyed properly or not, but to look at the content of the tapes and whether what was being depicted were criminal acts.”

Mukasey, however, has limited the probe, and the federal prosecutor named to lead it, John Durham, must seek further authority to examine questions such as who ordered the harsh interrogations, Anders said.

“Mukasey has kept Durham on a leash,” he said.

A U.S. Justice Department official said investigators “would have the authority to go wherever the evidence took them.”

Mukasey said FBI agents would conduct the probe under Durham. The bureau’s agents have raised concern over what they called abusive interrogations by the U.S. military at Guantanamo Bay prison and in Iraq.

Congress has launched its own investigations.

Bush, who has insisted he was unaware of the tapes until he was briefed last month, told Reuters last Thursday that he supported the Justice Department probe and “we will participate.”

White House and Justice Department officials, including former White House counsel and Attorney General Alberto Gonzales, played key roles in developing new policies on interrogation techniques.

CIA Director Gen. Michael Hayden has said the agency consulted with the Justice Department and “other elements of the executive branch” on the legality of its interrogation techniques.

Justice Department officials said it would not be unusual for White House officials to be questioned in any investigation.