The father of a man found dead in entertainer Michael Barrymore’s swimming pool 20 years ago has thanked witnesses who helped police in their latest investigation.

Terry Lubbock, whose 31-year-old son Stuart died during a party at Barrymore’s then home in Roydon, Essex, on March 31 2001, posted a thank you message on Twitter.

Essex Police arrested a man in March, on suspicion of the indecent assault and murder of Mr Lubbock, and released him without charge in August.

Terry Lubbock said in a tweet: “Thank you to all the new witnesses that have come forward they know who they are!

“I just want justice for Stuart nothing more.”

An Essex Police spokeswoman said in August that there was insufficient evidence for a “realistic chance of a successful prosecution”.

She said the arrested man, who was not named by police, had been released without further action.

A senior detective spoke of his regret.

Detective Chief Inspector Stephen Jennings said it was a “huge personal disappointment” to all those involved in the case.

“We have explored all possible lines of inquiry and sometimes, regrettably, the evidence is not yet there to issue charges.

“At every stage it is the Lubbock family and our search for justice for them that dominates our thoughts and our actions. We have tried our best. We will continue to try our best.

“For the last 20 years, as we have continually stated, two things have remained consistent.

“One is the commitment of Essex Police to deliver justice for Stuart and his father Terry; the second is that we believe of those present on the night Stuart died, someone at the house was responsible and someone knows what happened.”

A post-mortem examination showed that Mr Lubbock had suffered severe internal injuries which suggested he had been sexually assaulted.

Alcohol, ecstasy and cocaine were found in his bloodstream.

A coroner recorded an open verdict.

No-one has ever been charged in relation to Mr Lubbock’s death.

His 76-year-old father, who has been campaigning for justice for two decades, revealed earlier this year that he has terminal cancer.

Harry Clichy, a friend who has supported him in the campaign, said he is now seriously ill.

Barrymore, now 69, was arrested in 2007 but never charged with any offence.

He subsequently sued Essex Police, claiming his wrongful arrest had cost him about £2.5 million in lost earnings, but Court of Appeal judges concluded he should receive nominal damages.