edmund echukwu , 35 , was pulled from the water at a james bond-themed sex party at a £ 3million mansion in radlett , hertfordshire last friday night .
fellow revellers tried to revive him but he was pronounced dead at watford general hospital after emergency services were called .
it is believed mr echukwu is a nigerian from north london who was at his first swingers ' party at the eight-bedroom house that