President Bush may use an outside lawyer to represent him at the inquiry into the leaking of the identity of a CIA agent, the White House says.
Bush welcomed the inquiry, saying he wanted "to know the truth"
Mr Bush had contacted lawyer Jim Sharp and "in the event he needs advice he would retain him," spokesman Allen Abney said.
The move suggests Mr Bush expects to be questioned by the federal grand jury.
It looks into claims that White House staff blew the cover of Valerie Plame, whose husband opposed the Iraq war.
Since January, dozens of Bush administration officials have been interviewed, and the inquiry has extended beyond the White House to other government agencies, including the defence and state departments.
Disclosing a covert agent's name is a criminal offence in the US, punishable by up to 10 years in prison.
"The president has had discussions with an outside attorney," Mr Abney said in Washington.
White House press secretary Scott McClellan added that "the president has made it very clear he wants everyone to co-operate fully with the investigation and that would include himself".
Mr Bush earlier said he did not know who was the source of the leak.
But he urged White House staff to fully co-operate with the inquiry, saying he wanted "to know the truth".
Even though the president has a White House counsel, he is dependent on outside lawyers for private matters.
Act of revenge?
The allegations centre on last July's disclosure about Ms Plame, wife of Joseph Wilson, the former US charge d'affaires in Baghdad.
Before the war in Iraq, Mr Wilson was sent by the CIA to the West African state of Niger in order to investigate claims that Iraq had tried to buy nuclear material there.
His report concluded that there was no evidence for the claims.
Despite this, Mr Bush referred to them in his State of the Union address in January.
In a subsequent article in the New York Times, Mr Wilson questioned why his report had been ignored.
The White House later admitted it had been a mistake to include the claim in the address.
A week after Mr Wilson's article appeared, Ms Plame was exposed by journalist Robert Novak, who said he based his report on two unidentified senior administration officials.
A report in the Washington Post newspaper later suggested that White House officials blew the cover of Mr Wilson's wife in order to discredit him, by suggesting he had been given the Niger mission only at her urging.