Sandy Berger

Washington, July 21 (Reuters): Former national security adviser Samuel Berger, under investigation for removing classified documents from the National Archives, stepped aside yesterday as an informal adviser to Democratic presidential candidate John Kerry.

The probe of Berger, who served under former President Bill Clinton, escalated into an election-year firefight as Republicans accused Berger of stealing the documents for use by Kerry’s campaign and Democrats questioned the probe's timing. “Sandy Berger is my friend, and he has tirelessly served this nation with honour and distinction,” Kerry said in a statement. “I respect his decision to step aside as an adviser to the campaign until this matter is resolved objectively and fairly.”

Berger and one of his lawyers said he inadvertently removed copies of a classified memo and his handwritten notes on the material as he reviewed it to determine what Clinton administration-era documents could be turned over to the commission looking into the September 11, 2001, attacks.

Berger said he immediately returned the documents when he was told by the archives they were missing.

But one or more copies of a memo analysing the Clinton administration’s anti-terror efforts around the celebration of the millennium are still missing.

The FBI, executing a warrant, searched Berger’s office and home safe earlier this year.

Lanny Breuer, Berger's attorney, said he was told the government was appreciative of Berger's cooperation in the probe. “And then today, a couple of days before the 9/11 commission report comes out, the whole thing gets leaked,” he said.

Republicans accused Berger of removing the documents so they could be used by the Kerry campaign at a news conference on port security.