WASHINGTON — A Senate Democratic leader said Sunday the attorney general should appoint a special counsel to investigate the CIA's destruction of videotaped interrogations of two suspected terrorists.

Sen. Joe Biden, a Democratic presidential candidate and chairman of the Senate Foreign Affairs Committee, cited Michael Mukasey's refusal during confirmation hearings in October to describe waterboarding as torture.

Mukasey's Justice Department and the CIA's internal watchdog announced Saturday they would conduct a joint inquiry into the matter. That review will determine whether a full investigation is warranted. "He's the same guy who couldn't decide whether or not waterboarding was torture and he's going to be doing this investigation," said Biden, who noted that he voted against making Mukasey the country's top law enforcer.

"I just think it's clearer and crisper and everyone will know what the truth is ... if he appoints a special counsel, steps back from it," said Biden, D-Del.

That view was not shared fellow Democratic Sen. Jay Rockefeller of West Virginia, chairman of the Senate Intelligence Committee, who said Congress can get to the bottom of the matter. "I don't think there's a need for a special counsel, and I don't think there's a need for a special commission," he said. "It is the job of the intelligence committees to do that."

Republican Sen. Chuck Hagel of Nebraska, a member of the committee, echoed that sentiment.

The Senate and House intelligence committees are both investigating the destruction of the tapes and Hagel said one goal is to know whether justice was obstructed and who in the White House might have known about the fate of the tapes. Rockefeller, citing the confidentiality of certain intelligence briefings, said he could not comment on the existence of any other interrogation tapes.

On the presidential campaign trail, Republican Sen. John McCain of Arizona said destruction of the tapes "harms the credibility and the moral standing of America in the world again. There will be skepticism and cynicism all over the world about how we treat prisoners and whether we practice torture or not." Rival Mike Huckabee, a former Arkansas governor, questioned whether the action was taken for security purposes "or to cover somebody's rear end."

"If we're covering somebody's rear end, we need to expose their rear end and kick their rear end for doing something that's against the best interest of the United States," he said.

Biden asserted the "easiest, straightest thing to do is to take it out of the political realm, appoint a special prosecutor and let them decide, and call — call it where it is. Is there a criminal violation? If there is, proceed. If not, don't."

The spy agency's director, Michael Hayden, told CIA employees Thursday that the recordings were destroyed out of fear the tapes would leak and reveal the identities of interrogators. He said the sessions were videotaped to provide an added layer of legal protection for interrogators using new, harsh methods authorized by President Bush as a way to break down the defenses of recalcitrant prisoners.

The White House was scrambling over the weekend to determine who in the administration knew about the tapes and when. That includes Harriet Miers, who was a deputy White House chief of staff in 2003. Miers became White House counsel in early 2005; she left that job in January.

"I think that Hayden is not to be the judge of whether or not his ordering or his condoning the destroying of the tapes was lawful," Biden said. "It appears as though there may be an obstruction of justice charge here, tampering with evidence, and destroying evidence. And this is — I think this is one case where it really does call for a special counsel. I think this leads right into the White House. There may be a legal and rational explanation, but I don't see any on the face of it."

Hagel, a Republican often critical of the Bush administration on national security and Iraq, said he finds it hard to believe the White House did not know. "Maybe they're so incompetent" they didn't, he said. "I don't know how deep this goes. Could there be obstruction of justice? Yes. How far does this go up in the White House, who knew it? I don't know."

Bush "has no recollection" of hearing about either the tapes' existence or their destruction before being briefed about it Thursday morning, White House press secretary Dana Perino has said. She also said the president has "complete confidence" in Hayden's handling of the matter

The tapes showed interrogations of Abu Zubaydah, the first high-value detainee taken by the CIA in 2002. Zubaydah, under harsh questioning, told CIA interrogators about alleged Sept. 11 accomplice Ramzi Binalshibh. The two men's confessions also led to the capture of Khalid Sheikh Mohammed, who the U.S. government said was the mastermind behind the Sept. 11 terrorist attacks.

The other taped interrogations showed Abd al-Rahim al-Nashiri, the alleged mastermind of the 2000 attack on the USS Cole, which left 17 U.S. sailors dead. He and Zubaydah are now being held at Guantanamo Bay.

Biden spoke on "This Week" on ABC. Rockefeller and Hagel appeared on "Face the Nation" on CBS; McCain and Huckabee on "Fox News Sunday."