Sir Cliff Richard has threatened to sue the BBC for broadcasting archive footage of him with Jimmy Savile on Top Of The Pops.
The corporation used a clip from the programme during a report on News at Six last week about the inquiry into Savile's catalogue of sexual abuse at the BBC. In the clip, the DJ can be heard saying Sir Cliff's name. It was aired just after the reporter told of the "missed opportunities to stop" Savile.
After the broadcast, lawyers for the 75-year-old singer wrote to the BBC claiming it was defamatory. An email entitled "early legal warning" said: "The libel complaint says the inclusion of archive footage of Jimmy Savile stating the words 'Cliff Richard' is defamatory of Sir Cliff Richard, causing the viewer to believe that there were missed opportunities at the BBC to apprehend Cliff Richard for wrongdoing."
The BBC1 news item focused on Dame Janet Smith's extensive review into the "monstrous" campaign of sex abuse by Savile and TV presenter Stuart Hall while working for the BBC.
But it used the clip mentioning Sir Cliff even though Dame Janet's report has nothing to do with the singer.
It is understood that the complaint has prompted bosses at the BBC to warn staff not to use the film again.
One viewer wrote on Twitter: "Subtle of the BBC to show a clip of Savile introducing Cliff Richard on TOTP."
The threat of legal action follows the controversy surrounding the 2014 police raid on Sir Cliff's £2.5 million (NZ$5.2 million) Berkshire home, which officers let the BBC film after hatching a secret deal.
At the time, Sir Cliff's lawyers were considering suing the BBC for breach of privacy. A subsequent report concluded the BBC's actions had caused the singer "unnecessary distress".
Detectives have questioned Sir Cliff twice over historical sex assault allegations and have spent almost two years trying to gather evidence.
However, South Yorkshire Police has still not sent its case file to the Crown Prosecution Service, which will decide if the allegations against him are strong enough to press charges.
Sir Cliff is understood to have provided police with evidence that he was never alone with two of the men who allege he attacked them in the 1980s.
The singer, who completed a comeback tour to celebrate his 75th birthday last year, has denied the allegations.
The police are coming under increasing pressure to bring their inquiries to a conclusion, either by bringing charges against the star or by exonerating him.
The BBC declined to comment.