Police investigating the death of Stuart Lubbock during a party at Michael Barrymore’s Essex home offered a £20,000 reward in a fresh bid to find his killer.
Detective Chief Inspector Stephen Jennings said: “One or more of the eight people at this party are responsible for Stuart’s death.”
He added: “We know not everyone at that party was responsible for what happened, but someone was.”
Stuart was found dead in Mr Barrymore’s home on March 31, 2001, with tests later confirming he suffered internal injuries.
The guests who were at the party that night were, TV star Mr Barrymore, his then-boyfriend Jonathan Kenny, pal Justin Merritt and his sister Kylie, Claire Jones and Kelly Campbell as well as locals Simon Shaw and James Futers.
In his fresh appeal, Mr Jennings said: “We know not everyone at that party was responsible for what happened, but someone was.”
Mr Barrymore, 67, and two other men were arrested on suspicion of Stuart’s murder in 2007.
He later won legal action against the police for wrongful arrest in 2018.
Stuart’s cause of death was never established, with a 2002 inquest ruling an open verdict.
During the explosive briefing at Essex Police HQ, Mr Jennings said how vital evidence was removed from the crime scene.
Forensic teams, who took photos of the pool, found a thermometer hanging from a Jacuzzi at Barrymore’s home.
But, the next morning, it emerged it had disappeared along with a handle of an outhouse cupboard near the Jacuzzi.
Mr Jennings added: “These items could have been used in the assault.”
Stuart’s dad Terry Lubbock, 75, sat alongside Mr Jenning’s at yesterday’s press conference.
He believes the Crimestoppers reward appeal might see the case finally being solved.
Mr Lubbock, 75, said: “It’s time now for you to either clear your name or put your hands up.”
Daily Star Online has approached Mr Barrymore's representatives for comment.