The husband of a CIA agent whose identity was exposed during the debate over the Iraq war has accused the White House of being involved in a cover-up involving top aide Karl Rove.

Federal investigators are looking into who leaked the identity of Valerie Plame, whose name appeared in a newspaper column by journalist Robert Novak two years ago.

Mr Rove, the White House deputy chief of staff, who orchestrated Bush's presidential campaigns, has emerged as a source for at least one other media report on the case.

Ms Plame's husband, Joseph Wilson, said she was a victim of 'a cover-up of the ... web of lies that underpin the justification for going to war in Iraq'.

Mr Wilson is a career foreign service officer who served in the Clinton White House.

He went to Niger, in West Africa, in 2002 at the request of the CIA to investigate claims that Iraq was buying weapons grade uranium. Later he published a report saying there was no evidence to support the claim.

He claims the leaking of his wife's identity was aimed at discrediting him and the report.

A New York Times journalist is in jail for refusing to reveal the source of the leak. A reporter for Time magazine has confirmed that Mr Rove was a source for his reporting on Ms Plame's identity.