Daniel, 23, who was the boyfriend of Mr Malik's daughter Jessica, was found unconscious at the party in the garden of the Cranes Park home just after 7am on Friday, March 29.

Residents called an ambulance and tried to revive him, but he was pronounced dead at Kingston Hospital just before 8am.

Daniel was from Surbiton and had just qualified as a fire fighter and had been posted in Knightsbridge for two weeks.

A statement from his family read: "We are all completely devastated by this tragedy. Daniel had recently qualified as a firefighter and we were all very proud of his dedication and achievement.

"Daniel loved life and was loved so much by lots of people and we can never fill the gap we are left with."

A post mortem at Kingston mortuary on Friday confirmed the cause of death as drowning but further tests are being carried out to find out why he drowned. Police are not treating the death as suspicious.

DI David Way, of Kingston CID, said: "It appears that there was a party at the address and some of the people attending were swimming. The swimming pool was covered with a marquee and guests had been swimming in the pool.

"Last night 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 said that he and his family were trying to come to terms with the tragedy.