Police are continuing to question Michael Barrymore, along with two other men, about the death of Stuart Lubbock.
Michael Barrymore, 55, has been arrested by Essex Police
Mr Barrymore, 55, and the men, aged 37 and 32, were arrested on Thursday on suspicion of sexual assault and murder.
Mr Lubbock, 31, was found near the swimming pool at the entertainer's home near Harlow, Essex, in March 2001.
Mr Barrymore had hosted a party at the house in Roydon in the hours before Mr Lubbock's body was found. An inquest in 2002 recorded an open verdict.
Essex Police said the 37-year-old man had been arrested in Lancashire and the 32-year-old man was taken into custody in north Staffordshire.
The inquest into Mr Lubbock's death heard he suffered severe internal injuries which suggested he had been the victim of a serious sexual assault.
Alcohol, ecstasy and cocaine were found in his bloodstream.
An investigation was carried out by Essex Police after Mr Lubbock's body was found, but no-one was charged with any offence in connection with his death.
In December 2006, Essex Police began a new inquiry.
The Independent Police Complaints Commission (IPCC) also launched an investigation.
Stuart Lubbock's body was found by the side of the swimming pool
Following Thursday's arrests, the IPCC put on hold its inquiry into complaints made by the Lubbock family about the original Essex Police investigation.
Mr Lubbock's father, Terry, 62, of Harlow, said: "My life has been on hold. I will never get those six years back again. Why has it taken so long?
"I have had so many disappointments over the past six years. This could be another one. I am waiting for the jackpot. I am waiting with bated breath."
He said police had given him no warning of the arrests.
Mr Lubbock's lawyer, Tony Bennett, said: "What we've been campaigning for over the past 18 months is for somebody to be charged and brought to court."