Veteran DJ Tony Blackburn has accused the BBC of making him a "scapegoat" after he was sacked on the eve of the publication of a report into the culture at the corporation while sex offenders Jimmy Savile and Stuart Hall worked there.
The report by former Court of Appeal judge Dame Janet Smith is expected to condemn the BBC for its deferential culture and untouchable stars.
Mr Blackburn, 73, said "all relationships" he had with the BBC were "terminated with immediate effect" this week because his evidence to Dame Janet's review concerning an investigation in 1971 contradicted the BBC's own version of events.
He has pledged to take legal action against the corporation which he claims is making him a "scapegoat" for the "cover-up" of abuse.
The investigation in 1971 followed an allegation of assault made by the mother of a 15-year-old who later committed suicide.
Mr Blackburn says he was never interviewed over the incident but claims the BBC says he was interviewed twice.
In a statement released on Wednesday night, he said the decision to sack him had been taken by BBC director-general Tony Hall.
He said: "I am told that the decision was taken personally by the director-general. Quite naturally, I am devastated.
"The reasons for the BBC taking this decision are that my evidence to Dame Janet Smith shows, I believe, that a cover-up took place - one that I had no knowledge of. This goes against what the BBC believe.
"In 1971, allegations were made by the mother of a 15-year-old girl whose diary apparently contained suggestions that she had been seduced by celebrities including me.
"I am told that the mother told the BBC, a few weeks after her initial complaint, that her daughter had withdrawn the allegation against me.
"I have never seen the diary and neither has anyone at the BBC or the Dame Janet review.
"That same year this seemingly troubled teenager tragically took her own life.
"Dame Janet's report makes no suggestion that I was guilty 45 years ago of any misconduct whatsoever with this girl. Nor did a coroner's inquest or a subsequent police inquiry into her death.
"The BBC have made clear that they are not terminating my relationship with them because of any misconduct. They are destroying my career and reputation because my version of events does not tally with theirs.
"I was not guilty of any inappropriate conduct; my lawyers will take immediate action against anyone suggesting that I was.
"According to BBC records seen by Dame Janet, I was allegedly interviewed about the girl's diary before her death in 1971 by a very senior figure at the BBC, Bill Cotton Jr.
"I was also, supposedly, interviewed by Brian Neill QC as part of his report into the Payola scandal at the BBC.
"I have repeatedly told Dame Janet and the BBC I was never interviewed by either man in this context and the BBC records are either very vague or have, conveniently, disappeared.
"Regardless of these facts, the BBC is axing me after five decades of broadcasting.
"Sadly, what is happening to me now seems to be entirely in keeping with the past BBC culture of whitewash and cover-up.
"In 1967, I proudly opened Radio 1 for the BBC. Over the past 49 years I have enjoyed my time working for them immensely and I am grateful to my millions of listeners for their continued support over the decades.
"Sadly, despite being aware of my evidence for many months, if not years, the BBC have decided to make me a scapegoat and have taken away any future opportunity I have to broadcast for them.
"Naturally, I am now left with no choice but to take legal action against the BBC. They have taken away a career I love and I will not allow them to destroy my reputation."
The BBC declined to comment.
A leaked draft version of Dame Janet's report condemned the BBC for having managers who were "above the law".
Rapes, indecent assaults on boys and girls, and incidents of "inappropriate sexual conduct" with teenagers over the age of 16 were all "in some way associated with the BBC", the draft report said, adding that three of Savile's victims were only nine.
It also warned of the possibility that another "predatory child abuser could be lurking undiscovered in the BBC even today".
Dame Janet expressed disappointment at the leak last month and said the draft version was out of date.
Former Top Of The Pops presenter Savile, who died in October 2011 aged 84, was named as one of the country's most prolific sex offenders after hundreds of people came forward to say they were abused by him.
A year after his death, he became the subject of Operation Yewtree, a formal criminal investigation by the Metropolitan Police.
Hall, 86, was jailed in 2013 after admitting indecently assaulting 13 girls - one as young as nine - between 1967 and 1985.
His sentence was extended the following year when he pleaded guilty to two counts of indecently assaulting a teenage girl. The former It's A Knockout host was released from jail in December.
Dame Janet's review, which has reportedly cost £10 million, has been in contact with 775 people, interviewing 375 witnesses in connection with Savile and more than 100 about Hall.
The review was announced in October 2012 after the BBC faced criticism for ditching a programme about the late star's abuse.
Dame Janet's probe initially focused on the conduct of Savile, before it was extended to cover Hall in June 2013.
The findings were due to be published in April last year but were postponed at the request of the Met Police amid concerns they could prejudice ongoing investigations into sexual abuse.
Meanwhile Hall has hit out at "vindictive, malicious people" who accused him of sex crimes, as he spoke publicly for the first time since leaving prison.
In an interview with The Sun, he said he lived one day at a time and was grateful to still be alive.
He said: "To go from being a national treasure to the bottom of the pond has been very difficult. The vindictive, malicious people who have impugned me will think again. I'm hoping for fairness from everybody."