Police have warned Big Brother broadcaster Channel 5 over the risks of having a former police officer as a contestant.
Scotland Yard said it had contacted the television station after the Daily Star claimed a detective constable who it says "played a key role in Operation Yewtree" - the investigation into Jimmy Saville - will be appearing on the show.
Scotland Yard said it had made the broadcaster aware of "potential risks" to ongoing police investigations and reminded the company of its "responsibility".
More top news
Taha Hussain was 19 when he began sharing terror propaganda which said police and soldiers were among the "best of all people to kill".
Detectives have released CCTV images of people they want to speak to almost a year after Corrie McKeague vanished.
'Water Rats' gang leader killed after Briton murdered