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Democratic hopeful Sen. Joe Biden, speaking Sunday in Dubuque, Iowa, says he wants the CIA to explain destruction of tapes.

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 Relations 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 by 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.