Police were yesterday investigating the death of a man in a swimming pool at the Surrey home of actor Art Malik after a party to celebrate his daughter's 21st birthday.

Paramedics were called to the house in Surbiton at 7am yesterday after the 23-year-old, who is believed to have been the boyfriend of the actor's daughter, Jessica, was found unconscious in the pool. He was pronounced dead at Kingston hospital just before 8am.

Police sealed off the house and launched an investigation into the "unexplained death".

In a statement issued through detectives, Mr Malik, 49, who rose to fame in the 1982 TV series The Jewel in the Crown and appeared alongside Arnold Schwarzenegger in the action blockbuster True Lies, said: "Me and my family are trying to come to terms with this tragic event."

The evening had begun with a party at a nearby hotel before about 25 family and close friends returned to the large, detached house where Mr Malik, his wife of 22 years, Gina Rowe, and their daughters Jessica and Keira, live.

A marquee was set up over the swimming pool in the house's garden, and several guests were said to have been swimming. But police confirmed that no one else was in the water at the time the victim, an off-duty firefighter, entered the water.

More than 20 party guests were told to stay at the large, detached house as six officers from the Metropolitan police and 20 support police questioned them.

Detective Inspector David Way said: "The circumstances surrounding his death are not clear at this stage. However, the victim was found in the early hours this morning unconscious.

"Mr Malik is extremely shocked by this. We believe the young man is a very close friend of one of his daughters.

"It was the 21st birthday party for one of the residents of the house and what was supposed to be a celebration ended in tragedy.

"Mr Malik was at the address when we arrived and there were a number of adults present.

"We are searching the house and pool."