Lord Hutton said he deplored the leaking of his report to a newspaper as a political row raged about The Sun's revelations in yesterday's edition.
The premature disclosure of many of the law lord's findings sparked frantic denials from the Government and the former Downing Street communications director, Alastair Campbell, that they were responsible. Downing Street made it clear that it would co-operate fully with any leak inquiry.
Lord Hutton said he was considering "what investigative and legal action I should take in respect of the newspaper and its source".
The leak was particularly controversial because of the elaborate lengths to which Lord Hutton had gone to keep his findings secret. This, after all, was an inquiry itself prompted by two leaks: the "unauthorised" briefing of Andrew Gilligan and the identification of David Kelly as the reporter's source.
Speculation was rife at Westminster yesterday about the motives for the leak and who may have done it.
The Sun's political editor, Trevor Kavanagh, who got the story, was keeping a gnomic silence on the subject.
"Yes I received a phone call, but I'm not saying who it was from. There's no way if there is a police inquiry or any other sort of inquiry that we will reveal our source," he said.
Mr Kavanagh acknowledged that Mr Blair and Lord Hutton might be angry about his report, but added: "It's a story you couldn't possibly turn down ... if it is offered to you."
The Sun is believed to have had a team of reporters dedicated to getting the Hutton scoop and an "operation" at the printing works where the 328-page report was produced. Yet the Stationery Office, whose main press is in Southwark, London, goes to elaborate lengths to stop copies being stolen off the press. And it often prints sensitive government papers elsewhere.
At a media party on Tuesday night Sun executives were rumoured to have boasted about their scoop while implying that the source was at the top of government.
And as the first edition of The Sun hit the streets on Tuesday evening, there was frenetic activity in Downing Street. At 9:30pm No 10 issued a public statement denying it had told The Sun about the Hutton report's conclusions.
Heated negotiations began with The Sun began to get it to state publicly that Downing Street was not the source.
The Sun refused to specify who was behind the leak but it did agree to comply with Downing Street's request in part. On the end of the story a paragraph was tagged which stated: "The Hutton report was leaked to The Sun by someone who has no financial or vested interest in its outcome."
The Tory party assumed that the leak was from the government and its co-chairman issued a hasty statement shortly after 10pm. "The Government's fingerprints are all over the leaking of this document. It is a despicable act from a morally bankrupt Government," Liam Fox said.
It is easy to see why he drew that conclusion because the report looked so favourable to the Government. But as Downing Street pointed out, neither the Government nor Mr Campbell would have had any interest in leaking the report, partly because it would look too obvious. Both have categorically denied any involvement.
Like most Whitehall leak inquiries the identity of the source is likely to remain a mystery - unless, as in the case of Dr Kelly, a source owns up voluntarily.