Police gave details of Kelly's death which left little doubt it was suicide. His body had been found on Friday at a wooded spot near one of his favourite hiking trails.
"The post-mortem has revealed that the cause of death was haemorrhaging from a wound to his left wrist," a spokesman said.
Police said a knife and a packet of painkillers had been found near to where Kelly's body was found.
A BBC report in May cited an anonymous intelligence source as accusing aides to Blair of "sexing up" a government dossier on Iraq's alleged weapons of mass destruction to strengthen the case for war on which Blair has staked his reputation.
The government, which angrily rejected the report, said it believed Kelly was the source and he was grilled aggressively by a parliamentary committee on Tuesday.
"Events over recent weeks have made David's life intolerable and all of those involved should reflect long and hard over that fact," said a statement from Kelly's family issued on Saturday.
Kelly was sucked into the debate over the justification for war after the government said he might be the source for a BBC radio report.
During his appearance before the parliamentary committee, Kelly denied making allegations against Blair's officials. He was visibly shaken by the hearing, at which lawmakers called him a "fall guy" put forward to shield senior officials from blame.
His boss, Defence Minister Geoff Hoon, said the ministry had observed "proper procedures" in handling the affair.
"I am certainly aware that a great deal of effort was made by the Ministry of Defence to support Dr Kelly. Sadly, that has not been sufficient in these circumstances," he said.
But when asked by a television reporter whether he felt personal responsibility, Hoon was clearly rattled.
"I, and I know many others, have spent the last 24 hours trying to replay these terrible events in order to try and see whether something could have been done to avoid this tragedy. All I can say is that I will co-operate fully with the inquiry."
Kelly's death has ensured that accusations the Blair government exaggerated the threat from Iraq, and its alleged nuclear arms programme in particular, will not go away quickly.
Blair is likely to come under more pressure and face provocative questions such as one fired at him in Japan.
"Have you got blood on your hands Mr Prime Minister? Are you going to resign over this?" a reporter shouted. Blair responded with stony silence.
The public broadcaster, the BBC, has never said whether Kelly was the source for its report, in which it said a senior intelligence official had accused Blair's communications chief, Alastair Campbell, of ordering intelligence to be twisted.
Newspapers said the government had forced Kelly to come forward to clear "spin doctor" Campbell's name.
"Spun to Death", said front-page headline of the Daily Mirror newspaper.
"Yesterday a decent, shy civil servant who had been savagely chewed up and spat out by a malign, amoral Downing Street machine met a tormented and tragic end," the Daily Mail wrote.
There was criticism of the BBC too, which had refused to confirm whether or not Kelly was the "mole" for its report. The broadcaster continued to decline to comment on whether Kelly was the source on Saturday after police confirmed he was dead.
Many Britons outside world of politics and media appeared to conclude Kelly was a victim of all of them.
"The journalists and the politicians have got their victim, haven't they? There's a man dead. So why can't they just shut up now?" said Londoner Paul Hadley, listening to politicians and journalists slug it out on a radio chat-show on Saturday.
- REUTERS
Death of a civil servant, a casualty of war
British Parliament Foreign Affairs Committee transcript:
Evidence of Dr David Kelly
Key players in the 'sexed-up dossier' affair
Herald Feature: Iraq
Iraq links and resources
