The White House denied on Monday President George Bush's senior political adviser, Karl Rove, revealed to reporters Joseph Wilson's wife was an intelligence operative.
The former ambassador had previously told US media he had been tasked with investigating claims Iraq tried to acquire nuclear materials from Africa.
Wilson said he reported back to the administration the claims were “highly dubious” but the White House still used the suspect allegations to justify attacking Iraq.
But White House spokesman Scott McClellan derided what he called "ridiculous" accusations that Rove had then revealed the identity of Wilson’s wife to discredit him.
"This administration has played politics with national security for a long time but this is going too far"
General Wesley Clark,
Democratic presidential hopeful
"It is simply not the way the White House operates," McClellan said in response to newspaper reports White House officials were behind the disclosure, conviction for which could carry a 10-year prison term.
However, the Justice Department has launched a preliminary inquiry into the complaint and McClellan promised the White House would cooperate with the investigation.
The New York Times on Tuesday described the leak allegations as a "firestorm" that had come at a time "when even some Republicans in Congress are beginning to cast a more sceptical eye on the administration's use of intelligence to make its case against Iraq".
Independent inquiry urged
McClellan said there were no plans for an internal White House investigation
"There has been no information brought to us or that has come to our attention, beyond the media reports, to suggest that there was White House involvement," said McClellan.
Bush spokesman Scott McClellan
fends off a barrage of questions
Opposition Democrat politicians have called for a wider, independent probe into the affair, however, suggesting the Justice Department could face political pressure from Bush officials.
“This administration has played politics with national security for a long time but this is going too far,” Democratic presidential hopeful General Wesley Clark told Reuters.
Another Democratic presidential candidate and anti-war critic, Howard Dean, called for a full investigation, possibly by the independent inspector general of the Justice Department.
The Washington Post said over the weekend White House officials had leaked the name of Wilson's wife after the administration had asked him to look into claims Saddam Hussein had sought uranium in Africa, especially Niger.
Yet despite the Wilson’s findings and a warning by the US State Department's intelligence service, the accusation appeared in Bush's January State of the Union address.
In July, Wilson publicly revealed he had told Washington the information was false long before Bush’s speech. And the White House later admitted that Bush should never have made the uranium charge.
But a few days after Wilson's revelation, conservative writer Robert Novak quoted two senior administration officials in a nationally syndicated 14 July column as saying Wilson's wife was a CIA agent. The former diplomat has not confirmed his wife's occupation but has linked Rove to the leak.
A 1982 law makes it a crime - punishable by up to 10 years in prison - for someone with official access to classified information to identify intelligence officers intentionally to unauthorised people.