A 31-year-old killed himself by pulling a condom over his head in a bizarre internet drug ritual to increase sexual stimulation.

Gary Ashbrook was found naked on his bed beside several empty cans of nitrous oxide, a weak anaesthetic used for sexual gratification.

Mr Ashbrook, who was HIV positive, had been experimenting with the drug, known as laughing gas, with people he had met online.

He was found with an inflated condom over his head by his housemate, Michael Young, on May 13.

Speaking at an inquest at Eastbourne Magistrates' Court today, Mr Young said he found his friend in his room in Fullbrook Avenue, Newhaven, at about 8pm.

He said: "All he had said was that he had met a couple who had introduced him to nitrous oxide.

"He had been putting a condom over his head for two to three months.

"He had learnt this through some friends of his for sexual gratification."

Mr Ashbrook and Mr Young has spend the previous evening at home with friends eating pizza and watching the Eurovision Song Contest on TV.

Friend Paul Beaton, from Hove, said: "His family disowned him because he was homosexual and HIV positive.

"I knew he was into the sadomasochism bondage scene.

"I'm sure his death was an accident and he was probably only experimenting having only been recently introduced to nitrous oxide."

Friend Jennifer Dorney, from Crawley, said Mr Ashbrook initially hid his HIV status from his friends.

She said: "He was trying to find a job when he moved down to Newhaven.

"I found Gary to be a happy-go-lucky person who was really set in his ways.

"Apart from his HIV which I believe he had for some six to seven years he didn't have any other medical problems of which I was aware.

"I'm still unsure whether Gary's death was accidental or suicide."

Mr Ashbrook died from asphyxiation and left no suicide note.

A toxicology report revealed no traces of alcohol or drugs but nitrous oxide would not show up on tests.

East Sussex coroner Alan Craze, recording a verdict of death by misadventure, warned against the dangers of taking nitrous oxide.

He said: "I'm concerned about the use of nitrous oxide.

"He must have laid on his bed for a considerable amount of hours before he was found.

"I'm quite certain nitrous oxide was used and the danger was that would have predisposed to events subsequently going wrong.

"If people use nitrous oxide, in the same way as any other drug, and it is abused it carries with it considerable dangers.

"I'm quite satisfied there is no evidence or suggestion of suicide in this case."