A social worker who drowned at a James Bond themed swinger’s party was under water for minutes before bystanders attempted to rescue him as they thought he was “playing a game”.

Edmund Echukwu, 35, of Springwood Crescent, Edgware, was pulled from the pool at the three-acre mansion in the village of Radlett, near Borehamwood, in March last year.

A verdict of accidental death was returned for the Nigerian-born social worker at Hertfordshire Coroner’s Court on Thursday.  

A female witness, who cannot be named for legal reasons, described how she and Mr Echukwu had been dancing and chatting at the Theobald Street property before they decided to go for a swim in the large heated pool.

At one point near the centre of the pool, where it starts to deepen more severely, Mr Echukwu grabbed the witness, who was swimming with floats, around the neck.

She pushed him away and swam to the edge of the pool. When she turned around, Mr Echukwu was fully submerged with just his hand sticking out of the water.

The witness, who sobbed as she gave evidence at Hertfordshire Coroners Court, said she thought he was “playing a game”, and only began to think something was wrong when she heard another partygoer say “he’s been under way too long”.

Help was sought from the main house but it was several minutes before the owner arrived at the poolside and dived in to save him.

Several bystanders took turns administering CPR and mouth-to-mouth resuscitation in an attempt to revive the man but, despite their best efforts and those of paramedics who attended, Mr Echukwu was pronounced dead at Watford General Hospital 1.38am on March 28, 2015.

At the inquest, questions were raised about Mr Echukwu’s ability to swim. Before the two partygoers entered the pool, the woman asked if he could swim, to which he responded “I go with my boy”, referring to his son.

However another relative questioned by police said she did not think he could swim.

Mr Echukwu had been drinking alcohol at the “James Bond meets Pussy Galore” themed sex party, with a post mortem finding he had 81mg of alcohol per 100ml of blood in his system – fractionally above the drink-drive limit.

Despite this, the witness said he did not appear drunk.

Detective Constable Wood said police arrived at the scene at 0.49am on the night in question and established a crime scene perimeter. By then, many of the partygoers had already left, and many more gave incorrect phone numbers and addresses to avoid retrospective questioning.

However after considerable investigation the death was deemed not suspicious, and the coroner returned a verdict of accidental death by immersion combined with minor alcohol intoxication, which could have affected Mr Echukwu’s decision making in the water.