Spanish police are on the hunt for a 25-year-old man who Stephen Gately and his husband took home with them on the night the Boyzone star mysteriously died.

Gately and his partner Andy Cowles met a Bulgarian man named Giorgio at a gay nightclub in Palma last Friday night, and invited him back to their holiday home in Majorca afterwards.

It is not known if the man left Gately’s apartment before or after the singer died, but police believe locating Giorgio could help solve the mystery surrounding the death.

A police source told Britain’s Daily Mail: “We do not think this man is involved in any way in Stephen's death but his testimony could prove vital.”

Cowles, who married Dublin born Gately in a civil ceremony in 2006, found his 33-year-old partner dead on the couch on Saturday. The boyband star fell asleep on the sofa, and rumors say he died after choking on his own vomit after a night of drinking, though the Gately family denies this claim.

Cowles, who is said to be in a “terrible state,” attempted to revive his partner by giving him CPR, but to no avail.

A post-mortem examination will be carried out this week in Spain.

Boyzone members Ronan Keating, Keith Duffy, Mikey Graham and Shane Lynch flew out to Spain on Sunday night to visit the apartment where their bandmate Gately died.

In a statement, the Irish singers said they were left "completely devastated by the loss of our friend and brother, Stephen.”

"Stephen was a beautiful person in both body and spirit,” they said. “He lit up our lives and those of the many friends he had all over the world. Our love and sympathy go out to Andrew and Stephen's family. We love you and will miss you forever Steo."

Boyzone manager and “X Factor” judge Louis Walsh pulled out of the show’s live finals on Sunday, saying he was "very shocked and exceptionally upset.” Fellow “X Factor” judge Simon Cowell paid tribute to Gately on air, but said “the show goes on.”

“I can't believe he has gone,” Walsh said. “I'm in denial.”