WASHINGTON - Angry congressional Democrats demanded yesterday that the Justice Department investigate why the CIA destroyed videotapes of the interrogation of two terrorism suspects.

The Senate's No. 2 Democrat, Dick Durbin of Illinois, called on Attorney General Michael Mukasey to find out "whether CIA officials who destroyed these videotapes and withheld information about their existence from official proceedings violated the law."

Sen. Edward Kennedy, D-Mass., accused the CIA of a cover-up. "We haven't seen anything like this since the 18 1/2-minute gap in the tapes of President Richard Nixon," he said in a Senate floor speech.

And Senate Armed Services Committee Chairman Carl Levin, D-Mich., said the CIA's explanation that the tapes were destroyed to protect the identify of agents is "a pathetic excuse," adding: "You'd have to burn every document at the CIA that has the identity of an agent on it under that theory."

Democrats on the House Judiciary Committee sent letters to CIA Director Gen. Michael Hayden and Mukasey asking whether the Justice Department gave legal advice to the CIA on the destruction of the tapes, and whether it was planning an obstruction-of-justice investigation.

White House press secretary Dana Perino said yesterday that President Bush did not recall being told about the tapes or their destruction. But she could not rule out White House involvement in the decision to destroy the tapes, saying she had only asked the president about it, not others.

Perino refused to say whether the destruction could have been an obstruction of justice or a threat to cases against terrorism suspects. If the attorney general decides to investigate, "of course the White House would support that," she said.

In a daily press briefing dedicated almost solely to the topic of the CIA tapes, Perino responded 19 times that she didn't know or couldn't comment.

The spy agency destroyed the tapes in November 2005, at a time when human rights groups and lawyers for detainees were clamoring for information about the agency's secret detention and interrogation program, and Congress and U.S. courts were debating where "enhanced interrogation" crossed the line into torture.

Also at that time, the Senate Intelligence Committee was asking whether the videotapes showed CIA interrogators were complying with interrogation guidelines. *