Minutes after seeing an actor play him on stage this week in an adaptation of his no-holds-barred autobiography, Sebastian Horsley said: "They say seeing your doppelganger is an omen of death, so I got quite excited about that and thought, best get my coat on."

The extent to which the 47-year-old artist's unabashedly dissolute life imitated his art appeared to have reached a tragic zenith at 11am yesterday, when he was found dead by a girlfriend from a suspected heroin overdose in his flat in London's Soho, the corner of the capital whose seediness he sought to epitomise and whose gentrification he openly lamented.

His comment to The Independent two days ago at the review night of Dandy In the Underworld, the well-received play based on his memoir of the same name, reinforced speculation among friends that the opening of the production at the Soho Theatre was a significant factor in his death. After seeing the play, Horsley said: "I'd rather be crucified again than sit through that. I knew I was obnoxious but I never knew how much."

Scotland Yard yesterday said that it was treating the death as "non-suspicious at this early stage". It is understood that drugs paraphernalia were found near his body in the flat on Meard Street in the heart of Soho, where Horsley slept with many of the "more than 1,000" prostitutes he claimed to have spent time with at an accumulated cost of £100,000.

Habitually describing himself as a "dandy", Horsley had built a career out of his louche existence and his toe-curlingly frank writing about his dysfunctional family, addiction to heroin and crack cocaine, and penchant for paid-for sex.

Ivan Massow, the entrepreneur and former chairman of the Institute of Contemporary Arts, paid tribute to a "great friend". Mr Massow said: "He was your archetypal dandy, who loved people to think the worst of him. He was another larger-than-life Soho figure and it is sad that we are losing these last beacons of insanity."

The elder son of Nicholas Horsley, a lifelong Labour Party member who oversaw the transformation of Northern Foods into one of Britain's largest food companies as its chairman, Sebastian found himself on the fringes of the YBA (Young British Artists) movement and pursued extreme methods in his work.

His "artist as art" approach reached its height in August 2000 when he travelled to the Philippines to take part in a ritual where supplicants recreate the crucifixion. After refusing painkillers, he was nailed to the cross through his hands and feet before passing out. The extraordinary experiment in what Horsley called "method painting" ended when the footrest on the cross broke and he fell off, ripping through the flesh on his hands. A film and photographs of the gruesome event, along with the artist's subsequent paintings, were the basis for an exhibition in London in 2002. Talking then about the experience, Horsley said: "As an artist I don't want to paint things as they are but the way I feel and sense they are. I can only feel and sense how they are by undergoing the experience."

The artist claimed to have funded his existence through a fortune made on the stock market during the 1980s. Describing his attitude to his wealth, Horsley said he had "invested 90 per cent of my money in prostitutes, the rest on Class A drugs, the remains I squandered".

The writer, who once described himself as "half-Byronic, half-moronic; part-shaman, part-showman; half-Nazi, half-Liberace", attributed his passion for baring his backside to convention to his upbringing by alcoholic parents, who married after knowing each other for 13 days. His mother, Valerie, said in an interview shortly before her death: "I don't think Nicholas ever went to bed sober and I was always in a fog. Sebastian and my two other children were accidents and I drank all the way through my pregnancies. I tried not to be drunk when the kids came home from school."

In his autobiography, Horsley wrote of his family: "[My father] didn't give a toss about me. And I hated him. But I hated Stepfather even more. He was a tosspot. I'd come home to find him in bed with Mother, and Father in bed with someone else. Clearly everyone in my life who should have been vertical was horizontal."

Friends of Horsley, who was said to have been clean from drugs in recent months, last night insisted he was not filled with self-loathing and was unlikely to have taken his life. Toby Young, the journalist, said he initially believed the renowned flaneur might have faked his death in order to publicise the play of his memoir. Mr Young told the Daily Telegraph: "I have no doubt his death was an accident ... If it had been suicide Sebastian would not have passed up the opportunity to write a note. It's a tragic loss of life."

The Soho Theatre cancelled last night's performance of the one-man show as a mark of respect but said the production would continue as a tribute to its subject. Tim Fountain, the writer and director of the play, said there was a gulf between the public persona projected by Horsley and the private man. He said: "The real man was one of the sweetest, kindest, funniest people I ever had the privilege of meeting. But as Sebastian himself always said, he was hard-wired for extremes, and extreme ways of living bring with them great risks as well as rewards. I'm devastated."

Horsley missed few opportunities to further his reputation as a dilettante, writing a sex column for The Observer newspaper which was withdrawn after four months following complaints from readers about its graphic Easter Day descriptions of anal sex and revelling in an incident in March 2008 when he was denied entry to the United States on the basis he had dabbled in "moral turpitude".

The artist, who said he had worked briefly as a male prostitute and brothel keeper, had grown increasingly unhappy at what he saw as the decline of Soho as a centre of loose morals and bohemian bars, bemoaning the closure of haunts such as the Colony Room.

Speaking last week following the death of the Colony Room's last proprietor, Michael Wojas, Horsley told The Independent: "Ten years ago, on a good night here, you could get your throat cut. The air used to be clean and the sex used to be dirty. Now it is the other way round.