Vice President Cheney's chief of staff, Lewis "Scooter" Libby (search), has been pegged as a possible leaker of the name of CIA operative Valerie Plame (search) to a syndicated columnist, according to accounts in a book by former ambassador Joseph C. Wilson IV, Plame's husband.

In "The Politics of Truth," to be published Friday, Wilson says Libby is "quite possibly the person who exposed my wife's identity," according to The Washington Post, which obtained an early copy.

The vice president's office did not immediately respond Thursday to a request for comment.

Wilson writes that a "workup" of his background was done by the White House in March 2003, after his public criticism of the administration's Iraq policy.

"The other name that has most often been repeated to me in connection with the inquiry and disclosure into my background and Valerie's is that of Elliott Abrams (search), who gained infamy in the Iran-Contra (search) scandal," he writes.

Another suspect named in Wilson's book: White House chief political adviser Karl Rove (search). "The workup on me that turned up the information on Valerie was shared with Karl Rove, who then circulated it in administration and neoconservative circles," Wilson writes.

Columnist Robert Novak has said only that "two senior administration officials" were his sources.

Last October, White House spokesman Scott McClellan said his conversations with Rove, Libby and Abrams have ruled out their involvement.

A federal grand jury is probing the leak of the CIA (search) officer's identity. Subpoenas were issued to the White House on Jan. 22. The grand jury is attempting to find out if anyone violated a federal law that prohibits the intentional disclosure of the identity of an undercover agent by officials with security clearances.

Some critics have speculated that officials in the Bush administration had told reporters the name of the CIA officer to discredit her husband and his criticism of the administration's Iraq policy.