IT may never be known why a Benfleet man died at home after an inquest recorded an open verdict.
Experts were unable to establish why Terence Williams, 47, died even after sending away samples of mould spores found in his home for tests.
Mr Williams was found unconscious by paramedics in his home in Church Road, Benfleet, on December 8 last year, Chelmsford Coroners Court was told.
He was pronounced dead at the scene, but following a post mortem by Dr Simon Payne at Southend Hospital, the initial cause of death was given as unascertained.
The court heard he had a history of drug and alcohol abuse, but subsequent toxicology tests showed nothing in his system which would have killed him.
Coroner Eleanor McGann said: “Police attended and recorded no suspicious circumstances.
“The pathologist was unable to give a cause of death, so after histology and toxicology tests gave nothing, Dr Payne sought help from several expert consultants and there was prolonged and extensive testing.
“Dr Payne spent many months trying to find out why this gentleman died and even sent mould samples found at the property to be analysed in case there was something in that which killed him, but it was returned negative.
“I know he had a history of drug and alcohol abuse in the past, but that was not the immediate cause of death.
“I am afraid the death of Mr Williams will remain a mystery as it is unascertained and therefore the only verdict I can return is an open verdict.”