Tony Blair's former communications chief Alastair Campbell said he had been vindicated by the Hutton report into the death of Dr David Kelly.
Alastair Campbell was quick to respond to the Hutton report
He said that he had told the truth throughout the affair but accused the BBC of failing to do the same.
Mr Campbell said he hoped the media would now learn lessons from events last year.
"Today the stain on the integrity of the prime minister and the government has been removed," he said.
He added at a news conference in London: "What the report shows very clearly is this: the prime minister told the truth, the government told the truth, I told the truth.
"The BBC, from the chairman and director general down, did not."
He said that Lord Hutton had made clear that the allegations made by defence correspondent Andrew Gilligan on the Today programme and subsequently in the Mail on Sunday were "of the utmost gravity and were untrue".
The ex-spin doctor said it meant a "great deal" to his family and his former colleagues that Lord Hutton reached the conclusions he had.
It was precisely because of the BBC's reputation and authority that the allegations that the case for war with Iraq had been "sexed up" had such an impact.
"I find it hard to imagine a more serious allegation," he said.
"It has led to months of sustained questioning of my honesty and integrity in Parliament and the media and I am grateful to Lord Hutton for the clarity with which he has rejected the allegations against me."
He went on to say if criticisms of the sort levelled by Lord Hutton at the BBC had been levelled at the government there would have already been "several resignations at several levels".
Mr Campbell said he accepted he had become "too angry" on several occasions, but that did not affect the BBC's responsibility to look at his complaint properly.
"Had they done so, these events might have taken a very different turn," he said.
Mr Campbell - who is an ex-political editor of the Mirror newspaper - said as a former journalist and ex-government employee he had been on both sides of the fence.
"Having been in both journalism and politics, I would say this: if the public knew the truth about politicians, they would be pleasantly surprised," he said.
"If the public knew the truth about the way certain sections of our media operate, they would be absolutely horrified."
There were plenty of good journalists in the UK and it was in "the interest of everyone that the many good
journalists stand up against the bad".
He added: "All we ever wanted was an acknowledgement that the allegations broadcast on the BBC were false. Once the BBC decided to stand by its story, it
was bound to be a difficult and abrasive process."
On BBC Two's Newsnight programme he refused to answer questions on why the dossier on Iraq weapons appeared to be wrong.
He said: "The prime minister has set out the position on weapons of mass destruction.
"That is his job. He is the prime minister."
Mr Campbell also denied being the source of the leaked version of Lord Hutton's report in Wednesday's Sun newspaper.