Key allegations about the government's Iraq dossier reported by the BBC's Andrew Gilligan were "unfounded", Lord Hutton has said.
There were "uncertainties" in Mr Gilligan's evidence, said Lord Hutton
The judge said it was impossible to know exactly what government scientist Dr David Kelly had said to the journalist at their meeting last May.
But he said the allegation reported by Mr Gilligan that the government had "sexed up" the dossier with a claim about Iraq's weapons capability it knew to be untrue, was "unfounded".
The National Union of Journalists condemned the law lord's criticisms of Mr Gilligan as "unfounded."
Lord Hutton criticised "defective" BBC editorial processes over Mr Gilligan's report on BBC Radio 4's Today programme.
The judge said it was possible Dr Kelly did "not realise the gravity of the situation which he was helping to create".
"It may be that when he met Mr Gilligan, Dr Kelly said more to him than he had intended to say," he said.
'Threat to journalism'
But Lord Hutton said "uncertainties" arising from Mr Gilligan's evidence to the inquiry and the existence of two versions of notes from the journalist's meeting with Dr Kelly, meant he could not be definite about the pair's conversation.
In a live broadcast on the Today programme last May Mr Gilligan said the government "probably knew" it was wrong to claim Iraq's weapons of mass destruction could be deployed in 45 minutes.
He quoted his source as one of the senior officials in charge of drawing up the dossier.
Mr Gilligan accepted during cross-examination at the Hutton inquiry his words were "imperfect".
He said his intention had been to make an allegation of spin rather than dishonesty.
Lord Hutton rejected the idea the dossier had been "sexed up".
He said the 45-minute claim was based on an intelligence report the Intelligence Service believed to be reliable.
It had been included in the September dossier with the Joint Intelligence Committee's approval.
Mr Gilligan said the 45-minute claim had not been included in the dossier at first because it only came from one source and the intelligence agencies said they did "not really believe it was necessarily true".
But Lord Hutton said this claim was included later because the intelligence had not been received until the last minute.
The NUJ's general secretary Jeremy Dear said: "I have spoken to Andrew Gilligan today and I believe the report does him and his story a grave injustice.
"Whatever Lord Hutton may think, it is clear from the evidence he heard that the dossier was 'sexed up', that many in the intelligence services were unhappy about it, and that Andrew Gilligan's story was substantially correct.
"From Andrew Gilligan's 19 broadcasts on that first morning, Lord Hutton has taken a single sentence barely noticed at the time, and has used it to condemn the entire story," he said.
The union called on the BBC to join the NUJ in defending Mr Gilligan.