The main investigative committee in the Republican-led House will look into allegations Clinton administration national security adviser Sandy Berger (search) mishandled highly classified terrorism documents, lawmakers said Wednesday.

Even though the matter already is the subject of a Justice Departmen criminal probe, House Government Reform Committee Chairman Tom Davis (search) said the panel has "a constitutional responsibility to find out what happened and why."

"At best, we're looking at tremendously irresponsible handling of highly classified information," said Davis, R-Va.

House Speaker Dennis Hastert (search), R-Ill., said the questions the committee should answer include whether there was any attempt to cover up embarrassing materials, what happened to documents removed by Berger that are still missing and what security risk the entire episode poses.

The decision by House leaders to launch a congressional investigation came the same day the White House acknowledged that its lawyers were notified months ago about the Berger investigation. In yet another development, the chairman of the Democratic National Committee filed a Freedom of Information request for any correspondence about the probe between the Justice Department and the White House.

DNC chairman Terry McAuliffe said he was making the request "in response to the questionable timing of the public release of information," which was the subject of a story by The Associated Press three days before Thursday's scheduled release of the final report by the Sept. 11 commission.

The panel's final report is expected to be critical of both the Bush and Clinton administrations' response to terrorist threats before Sept. 11. But Bush has much more to lose from a negative report because he is seeking re-election this year.

"The fact that the Bush White House knew about this for months absolutely smells," DNC spokesman Jano Cabrera said. "It looks like they leaked this to provide themselves with political coverage."

Justice Department officials refused to comment on whether prosecutors provided such information. It is routine for the proper agency to be notified when there is a criminal probe involving that agency's classified documents, according to current and former law enforcement officials.

The documents in the Berger case originated with the White House National Security Council and dealt with actions and recommendations stemming from the threat in 1999 of a terrorist attack during the 2000 millennium celebrations. The documents, written by former NSC aide Richard Clarke (search), were classified at the extremely sensitive "codeword" level, which is above the classification level for the nation's nuclear secrets.

White House spokesman Scott McClellan told reporters that, months ago, "some officials in our counsel's office were contacted as part of the investigation. The counsel's office is the one that is coordinating with the Sept. 11 commission the production of documents and since this relates to some documents, the counsel's office was contacted as part of that investigation."

The president had little to say, telling reporters who asked him what he had learned about the probe: "I'm not going to comment on this matter. This is a serious matter."

Berger was reviewing the materials in 2003 to help determine which Clinton administration documents to provide to the Sept. 11 commission. In a statement Tuesday, Berger said he made "an honest mistake" but was innocent of any wrongdoing. Berger has said he must have discarded the missing documents.

Former Republican Sen. Warren Rudman of New Hampshire said he understands the documents involved are copies and that the originals are available, adding, "I have known Sandy Berger for a long time and I find it very difficult to ascribe any sinister motive for what he did."