Sir Cliff Richard is demanding to know how the BBC knew that he was under investigation for an alleged sexual assault.
The 76-year-old is suing the BBC over reports in which he was named as a suspected sex offender while officers were raiding his apartment in Sunningdale, Berkshire, in August 2014.
During a court hearing yesterday his lawyers called for BBC bosses to disclose whether the source of information was someone working on a wider Metropolitan Police inquiry into sex abuse allegations, which is codenamed Operation Yewtree.
BBC editors do not want to reveal the detail Sir Cliff is asking for and say journalists have to protect sources.
A judge analysed arguments from rival lawyers at a High Court hearing in London yesterday and a decision will be announced in the near future.
Sir Cliff is taking legal action against both the BBC and South Yorkshire Police over coverage of a raid at his apartment, claiming he has suffered 'profound and long-lasting' damage.
The entertainer was placed under investigation in 2013 when a man made an allegation to the Metropolitan Police, claiming he was sexually assaulted by Sir Cliff at a Christian rally in Sheffield in 1985 when he was 16.
Metropolitan Police officers passed the allegation to South Yorkshire Police in July 2014.
Sir Cliff denied the allegation and, in June 2016, prosecutors announced he would face no charges.
The raid on Sir Cliff's apartment was broadcast live after South Yorkshire Police provided the BBC with details of the operation.
The force claims the BBC already knew about the police probe into the allegation.