The Justice Department should administer a polygraph test to former National Security Adviser Sandy Berger to find out what documents he took from the National Archives in 2002 and 2003, Rep. Tom Davis wrote in a letter to Attorney General Alberto Gonzales dated Monday.

Davis, ranking Republican on the Committee on Oversight and Government Reform, is leading a group of 18 lawmakers who say the Justice Department has been "remarkably incurious" about Berger's decision to remove documents relating to the Sept. 11 commission's inquiry into his role in helping prevent terror attacks during the Clinton administration.

"It is extraordinarily important that the Justice Department avail itself of its rights under the plea agreement and administer a polygraph examination to Mr. Berger to question him about the extent of his thievery. This may be the only way for anyone to know whether Mr. Berger denied the 9/11 commission and the public the complete account of the Clinton administration's actions or inactions during the lead up to the terrorist attacks on the United States," Davis wrote.

The letter was signed by all Republican members of Congress.

Berger admitted to taking documents on two of the four occasions he went to the National Archives to bone up on his responses for the Sept. 11 commission on his inquiry into how intelligence and law enforcement communities failed to prevent the Sept. 11, 2001, terror attacks on the United States. He said he hid some of them at a construction site near the archives building in Washington.

Berger agreed to take a polygraph test as part of a plea deal reached in September 2005. As part of the guilty plea, he was also sentenced to 100 hours of community service, two years probation, three years of lost security clearance and a $50,000 fine plus court costs.

A report issued two weeks ago by Davis said commission members expressed grave concerns about whether they had received all the relevant information on the Clinton administration's anti-terror activities. Archivists said they will never know what Berger took because none of the pages Berger said he took were inventoried.

At the time of the report, Justice Department spokesman Bryan Sierra said the department "has no evidence that Sandy Berger's actions deprived the 9/11 commission of documents, and we stand by our investigation of this matter."

Added Matt Bennett, a spokesman for Berger attorney Lanny Breuer: "I can state unequivocally that no documents were withheld, and that all documents that Mr. Berger took were disclosed to the Justice Department and the inspector general of the archives."

But Davis and the other lawmakers said the Justice Department's investigation is incomplete and two Justice Department officials confirmed that a polygraph was never administered despite the department being given the authority to do so.

FOX News' Molly Hooper and The Associated Press contributed to this report.