Top Clinton Aide in Secrets Row

President Clinton's national security adviser, Sandy Berger, is under criminal investigation for having removed top secret counter-terrorism documents from the US national archives, it was reported yesterday.

Mr Berger said he inadvertently took home classified material in his pockets after reviewing Clinton-era documents, blaming it on his own sloppiness.

He denied attempting to withhold or hide documents from a commission looking into the September 11 terrorist attacks, which is due to publish its report tomorrow, and which is expected to criticise the failure of both the Clinton and Bush administrations to do more to combat al-Qaida and prevent the attacks.

Mr Berger, who yesterday stepped down from his role as a foreign policy adviser to Senator John Kerry, returned most of the missing documents, which concerned his own security recommendations in the wake of the foiled al-Qaida "Millenium Plot" to attack Los Angeles airport and other targets in early 2000.

However, some papers were still missing yesterday, and Mr Berger said he may have thrown them away accidentally. Mr Berger's home and office were searched by FBI agents this year, and administration officials said he was the subject of a criminal investigation but added that no decision had been made to charge him.

Democrats angrily pointed to the timing of the government leak to the Associated Press on Monday night, pointing out that the investigation was launched last October, but only surfaced this week in the run-up to the September 11 commission report.

The intention, they claimed, was to divert attention from the report, which is expected to be critical of the Bush administration for failing to track down the al-Qaida hijackers before the attacks.

Robert Boorstin, a former aide to Mr Berger, told the Guardian: "This is an attempt to take Sandy out and off the TV when it comes to reacting to the 9/11 commission.

"He knows more about what Clinton did against terrorism than just about anyone else. How convenient for him to disappear."

However, Al Felzenberg, a spokesman for the bipartisan commission, said the incident had not affected its work or its conclusions. "The stories we're reading about now in no way impacted on the commission's ability to do its work," he said. "It has had access to everything ... that it needs to do its job."

US news reports yesterday quoted government officials as saying the investigation into Mr Berger began when archive staff saw him putting material into his jacket and trousers. CNN said it had been told by two unnamed officials that he had been seen stuffing documents into his socks.

One of Mr Berger's lawyers, Lanny Breuer, denied the charge, insisting his client had not sought to conceal anything. He said Mr Berger believed he had been looking at copies of classified documents rather than originals.

He also took away handwritten notes without permission, a violation of archives policy. "In the course of reviewing over several days thousands of pages of documents on behalf of the Clinton administration in connection with requests by the September 11 commission, I inadvertently took a few documents from the archives," Mr Berger told Associated Press.

"When I was informed by the archives that there were documents missing, I immediately returned everything I had except for a few documents that I apparently had accidentally discarded."