The father of Stuart Lubbock has said he is "dismayed" his bid for a fresh inquest into the death of his son at Michael Barrymore's home has been blocked.
Attorney General Jeremy Wright rejected Terry Lubbock's application, saying there was no new evidence likely to overturn the open verdict returned at the original inquest in 2002.
Mr Lubbock, 31, was found floating face down in the pool at Mr Barrymore's luxury home in Roydon, Essex, on March 31 2001 after attending a party there.
His father, who is now in a care home after suffering four strokes, said he only learned of the decision after being phoned by a Daily Mirror reporter.
The 73-year-old, of Harlow, Essex, said: "I was thinking about dropping it anyway because it's taken 17 years of my life - look where I've ended up.
"I've had it going through my head for 17 years - it won't be easy to put it to rest but I have got to try.
"I'm totally and utterly dismayed by the police and justice system. I'm gutted, I really am.
"Seventeen years of my life and I've ended up in a care home."
He said he believed the case was "definitely" responsible for the decline in his health and the decision was likely the end of his legal fight.
"You would think they would have had the decency to phone me and tell me," Mr Lubbock added.
"As far as I'm concerned it is the end. If anybody out there can do anything to keep it going I would welcome that."
An application for a fresh inquest may be made only with the authority of the Attorney General, who provides it only if he is satisfied there is sufficient evidence to offer a reasonable prospect of the Court ordering a new inquest.
Announcing his decision, Mr Wright said: "I offer my deepest sympathy to the family of Stuart Lubbock for their loss, but, as disappointing as it will be for the family, it would not be right to pass this matter to the High Court when the tests for a new inquest are not met."
Medical experts told the 2002 inquest in Epping that he had suffered severe internal injuries, suggesting he may have been the victim of a serious sexual assault.
Alcohol, cocaine and ecstasy were found in his system.
Mr Barrymore, who was one of the biggest TV stars of the 1980s and 1990s with shows like Strike It Lucky, Barrymore and My Kind Of People, was arrested in 2007 on suspicion of rape and murder.
Essex Police later admitted his detention was unlawful as the arresting officer did not have reasonable grounds to suspect the performer was guilty.
The force was ordered to pay damages to Mr Barrymore, who said the arrest had destroyed his career.
Terry Lubbock launched a bid for a new inquest last year, claiming new evidence was available which might lead to a different result.
In a statement released on Thursday, Mr Wright said he had concluded that none of the grounds of challenge set out in the application had a reasonable prospect of success.
"As there is no fresh evidence that will likely lead to a different outcome being recorded on the inquisition he would not be able to provide his authority for the applications to be made to the High Court," said the statement.