For the second day in a row, administration officials said yesterday that more of President Bush's aides knew about an investigation of former Clinton national security adviser Samuel R. "Sandy" Berger than the White House originally acknowledged.

The question is sensitive because Democrats have charged that Republicans leaked word of the investigation to try to taint next week's Democratic National Convention and to distract attention from criticisms of Bush in the report of the commission investigating the attacks of Sept. 11, 2001.

A senior administration official, who spoke on the condition of anonymity, said that some National Security Council officials knew Berger -- who has resigned from his position as informal adviser to Democratic presidential candidate John F. Kerry -- was suspected of mishandling National Archives documents that were being sought by the commission.

National security adviser Condoleezza Rice, meeting reporters to discuss the commission's report, would not say when she was told of the probe.

"Sandy is somebody I've known a long time," Rice said. "And I think he's a good person, and I respect him. This is a criminal investigation. It's a serious matter. I'm just not going to comment about it."

The senior official said that a few NSC staff members who also report to the counsel's office had known about the inquiry.

On Wednesday, a day after saying he learned about the investigation from news reports, White House press secretary Scott McClellan added that "a few individuals" in the White House counsel's office had known about the inquiry. He said that was because the counsel's office was coordinating document production with the Sept. 11 commission.

Former Clinton press secretary Joe Lockhart, who is serving as a spokesman for Berger during the controversy, said the expanding circle of officials who the White House acknowledges knew of the criminal investigation heightens his suspicion about the timing of the disclosure that Berger is under investigation.

"This is the third day in a row that the story has changed," Lockhart said. "Did the political operation know? Did [adviser] Karl Rove know? I think it's time for them to come clean, say what they knew, when they knew it, and what role if anything they had in leaking it."

Berger has acknowledged removing copies of a classified "after-action report" that he had ordered to study the Clinton administration's handling of terrorist threats at the time of the millennium, but he said the removal was unintentional. He returned some copies after being contacted by Archives officials, but some documents are missing and were apparently discarded.

The narrowly averted millennium threat, aimed at Los Angeles International Airport and a Western hotel in Jordan, resulted in White House anti-terrorism coordinator Richard A. Clarke's preparation of the after-action review. It recommended building agent capabilities at the CIA and dramatically tightening immigration rules and border protections.

The Sept. 11 commission report said the recommendations generated an internal tug of war over CIA funding, with the agency finally getting a modest supplemental appropriation.

Also yesterday, Bruce R. Lindsey, who serves as former president Bill Clinton's liaison to the Archives, said he was not alerted to concerns about missing documents until two days after Berger's Oct. 2 visit. Berger was notified that day, and he searched his office for the missing papers. A government source claiming knowledge of the investigation said Archives officials alerted Lindsey to concerns after a visit by Berger in September. Lindsey said yesterday this was not the case.

Staff writer Susan Schmidt contributed to this report.

Sandy Berger took Archives documents.