Mr Lubbock, 31, died following a party at the home of entertainer Michael Barrymore, 68, in March 2001.
In a statement, Essex Police said: “Detectives have today, Wednesday 17 March, arrested a 50-year-old man in connection with the indecent assault and murder of Stuart Lubbock.
“The man, who was arrested in Cheshire, remains in custody where he continues to be questioned.
“Stuart was found unconscious in the swimming pool of a property in Roydon on March 31 2001.
“Despite attempts to save him he later died in hospital. The 31-year-old had been attending a party at the house with eight other people.
“A post-mortem examination found Stuart had suffered horrific anal injuries which are believed to be the result of a serious sexual assault prior to his death.”
Butcher Mr Lubbock, 31, had been attending a party at Barrymore’s luxury home in Roydon in Essex, two miles from Harlow, with eight other people on March 31, 2001.
Barrymore was criticised for leaving his home soon after Mr Lubbock was found floating in the outside pool.
The 68-year-old former television presenter – who became a household name for shows such as Strike It Lucky – has always denied involvement in the death.
A post-mortem examination showed Mr Lubbock had suffered severe internal injuries which suggested he had been sexually assaulted.
Alcohol, ecstasy and cocaine were found in his bloodstream.
(More to follow)