President Bush said Thursday he has consulted with a private attorney and is willing to cooperate with the grand jury investigation of who leaked the name of a covert CIA operative last year.

The attorney is Jim Sharp (search), a Washington trial lawyer and former federal prosecutor.

"If I deem I need his advice, I'll probably hire him," Bush told reporters in the Rose Garden. "This is a criminal matter, it's a serious matter."

"I want to know the truth," Bush added. "I'm willing to cooperate myself."

Bush has expressed doubts in the past that the government's investigation will pinpoint who was responsible for the leak.

A federal grand jury in recent months has questioned numerous White House and administration officials to learn who passed along the name of CIA operative Valerie Plame (search), wife of former Ambassador Joseph Wilson (search), to the news media.

Disclosure of an undercover officer's identity can be a federal crime.

Wilson has said he believes his wife's identity was disclosed to attack his credibility because he criticized Bush administration claims that Iraq had tried to obtain uranium from Niger. Wilson went to Niger for the CIA to investigate the information about Iraq and he found the allegation to be highly unlikely.

Sharp has been an attorney in the nation's capital for the better part of three decades.

"I practiced law with Jim for many years and he's a very talented and experienced lawyer and will serve the president well," said longtime white-collar criminal defense attorney Tom Green, whose clients have included figures in major Washington controversies, including the Iran-Contra affair.

Asked about the leak investigation, Vice President Dick Cheney's (search) office said that if the vice president were to seek counsel on any issue, he would do so with Terrence O'Donnell, a senior partner in the Washington law firm of Williams & Connelly. Cheney has consulted with O'Donnell for years.

The probe is being handled by Chicago U.S. Attorney Patrick Fitzgerald, appointed after Attorney General John Ashcroft (search) stepped aside from case because of his political ties to the White House.

Plame's work for the CIA was first revealed by syndicated columnist Robert Novak, who wrote that two administration officials said Wilson's wife suggested sending him on the Niger trip.

Wilson went public regarding Niger in March 2003, and in a New York Times op-ed commentary on July 6, 2003, Wilson disputed Bush's statement in his State of the Union address that Iraq was trying to develop a nuclear bomb and had sought to buy uranium in Africa. Plame's identity surfaced eight days after the New York Times commentary ran.

Wilson has suggested in a book that the leaker was Lewis "Scooter" Libby, chief of staff to Vice President Cheney. But Wilson's book, "The Politics of Truth," gave no conclusive evidence for the claim.

The White House denied the claim and accused Wilson of seeking to bolster the campaign of Democrat John Kerry, for whom he has acted as a foreign policy adviser.

Absent a breakthrough from the documents or a cooperating witness, prosecutors may be forced to try to identify the leaker through Novak or other reporters. However, journalists pressed by the prosecution could assert a First Amendment privilege to protect their sources.