Lewis Libby: A shy insider exposed to the glare of bad publicity

Indeed, Mr Libby, 55, has a reputation as a government insider with a sense of discretion. While the world now knows that he did on occasion talk to the press - notably to Judith Miller of The New York Times - he never allowed his name to be used. Normally, said the columnist Bill Kristol, he would end up "telling you absolutely nothing." Not at all in the mould of Karl Rove, another subject of the inquiry, who cuts a far more partisan figure in Washington, Mr Libby shied from political point-scoring. But while he remained mostly in shadows, he was said to be joined at the hip to his boss.

Mr Libby is said to have played a vital role in the launch of the war in Iraq, at one juncture circulating documents in the White House purporting to show that Iraq had weapons of mass destruction.

At Yale, Mr Libby's political science teacher was Paul Wolfowitz, an architect of the neocon revival under President George Bush and now head of the World Bank. He joined the Pentagon under the elder Bush's presidency. It was at the Pentagon that the relationship with Dick Cheney, then Secretary of Defence, was founded.

Mr Wolfowitz said Mr Libby had never been "a rabidly partisan political type".He has never publicly revealed the full form of his name - some say it is Irv - while stories of where "Scooter'' come from vary. Most surprising, perhaps, was his sideline in novel-writing. In 1996, he published a book called The Apprentice.