Tony Blackburn was fired because his evidence to the Jimmy Savile sex abuse inquiry "fell short" of the standards demanded, BBC director-general Lord Hall has said.
The veteran DJ, who has accused the BBC of making him a "scapegoat", denied in evidence that he had ever been made aware by the BBC of a complaint against him by a teenager in 1971 even though the corporation told the inquiry he had been.
Dame Janet Smith, in her inquiry report, said she "preferred" the evidence that Blackburn was in fact interviewed by BBC officials about the complaint despite his denial.
The allegation, which Blackburn has strenuously denied, was that he "seduced" teenager Claire McAlpine after inviting her back to his flat following a recording of Top Of The Pops.
In a statement, Blackburn said he had been told that the girl's mother told the BBC, a few weeks after her initial complaint, that Claire had withdrawn the allegation.
The 73-year-old also said Dame Janet's report made no suggestion he was guilty of misconduct with the teenager, nor did a coroner's inquest or a subsequent police inquiry into her death after she took her own life.
But Lord Hall said the corporation had "parted company" with Blackburn because of his evidence to the inquiry.
Asked why the BBC sacked the DJ, and he said: "Look, put this in context. This is one of the most important inquiries in the BBC's history. And that has put an even greater responsibility on everyone who took part in that inquiry to co-operate fully and to be open.
"So many survivors and witnesses have honestly and openly co-operated fully and at great personal cost to themselves.
"As Dame Janet has said, she's rejected his evidence, and she has explained very clearly why.
"I have to take that extremely seriously. My interpretation of that is that Tony Blackburn fell short of the standards of evidence that such an inquiry demanded.
"I am making no judgment or accusations about events or behaviours about what happened in the past, but simply about what he's done now and what he was doing in front of this really crucial inquiry."
The complaint about Blackburn started life as an internal BBC matter, but was soon to become a matter of public interest and concern.
The report said: "Shortly afterwards, Claire McAlpine committed suicide and, on the Sunday following her death, the News of the World carried a front page piece suggesting, in effect, that her death was directly connected with her association with Top Of The Pops."
Blackburn has pledged to take legal action against the corporation, which he claims is making him a "scapegoat" for its own "cover-up" of abuse.