A man died suddenly in York when an infection caught from injecting steroids took hold in his heart, an inquest has heard.
Andrew Johnson, an instructor at the city's Fitness First, was just 34 when he died in February last year.
It emerged at his inquest that his sudden death was most likely caused by a virulent infection picked up from injecting steroids, even though Mr Johnson was "fastidious" about hygiene and took great care to use sterile and safe equipment.
Coroner Jonathan Leach recorded a verdict of accidental death at an inquest at New Earswick Folk Hall on Tuesday.
Mr Johnson was found dead in his bedroom by his girlfriend and landlord, after mounting concerns that he could not be contacted on Sunday, February 22 last year.
He shared the house in Rawcliffe with two other men, but had not been seen or heard since getting in from a night out in the early hours of that morning.
A keen body builder, Mr Johnson was known to inject steroids to maintain his physique, but both his mother and girlfriend told the coroner that he took enormous care to use hygienic equipment and sterile needles.
However, consultant pathologist Dr Andrew Clarke told the inquest that the only clue to death lay in the drug use.
Dr Clarke said although the "paraphernalia" of needles and syringes were meticulously laid out in Mr Johnson's gym bag, he could find no sign of any sterile wipes he could have used to clean the small rubber cap over the vial of steroid.
He said: "There was no form of sterilising swab, which was unusual given all the other paraphernalia there. Although he was using sterile needles, there was no mechanism of cleansing the vial or the rubber cap to the vial of liquid he was injecting himself with. It is most likely the cap got infected."
Because of this, he told the coroner that he believes Mr Johnson, who was originally from Stockton-on-Tees, contracted a dangerous bacterial infection from something as simple as dirt on his finger passing on to the bottle top.
Dr Clarke said that even though Mr Johnson was careful to change needles between drawing the liquid into the syringe and injecting himself, the infection could have got from the cap into the liquid, and from there into his blood stream and ultimately his heart tissue.
In 20 years of practice, the pathologist said he had never seen such a large growth of bacteria in a person, and once the bacteria had begun to multiply in his heart it would have interfered with the the way it worked, meaning Mr Johnson "effectively had a heart attack" and would have been unlikely to have known what was happening, Dr Clarke added.
He went on to tell Mr Johnson's parents that it was unlikely some chest pains their son felt some months earlier had anything to do with his death.
The bacteria could have circulated in his blood stream - probably for at least 24 to 48 hours before his death - causing no symptoms until it affected his heart.
Dr Clarke added: "If it had been diagnosed, it would have been treatable. The problem is that when an organism grows through the conducting tissue of the heart it interrupts the conducting mechanism of the heart and stops the natural beating and death is instant."
Laboratory tests on Mr Johnson's heart tissue found the organisms were clostridium limosum, a bacteria widely found in soil and faeces.
His girlfriend, Kerry Holder, told the inquest that Mr Johnson had tried to cut down his steroid use since they met around four months before his death. The inquest heard that Mr Johnson was separated from his wife.