During an inquest hearing yesterday, the St Pancras coroner, Dr Stephen Ming Chann, said to the magazine's deputy editor, Angus MacKinnon: "I understand this was a suspected overdose?" Mr MacKinnon replied, "Yes."
A full inquest will be held later. Conde Nast Publications, GQ's publishers, said he had had "probable heart failure".
The American-born journalist joined the magazine as features editor when it was launched in 1988. He combined news-based features with articles on fashion, leisure and what colleague described as "neat shit to buy". Under him, circulation climbed by 40 per cent to about100,000.
Friends described him "gregarious, larger than life". A colleague said: "You can't talk about Michael without smiling."
Rosie Boycott, editor of rival magazine Esquire, said: "He was fab and this is horrible news. Five years ago, there was no men's magazine sector. People used to look at us and say 'you're flash in the pan, overnight, you'll never sell more than 50,000.' In the course of the past two years, that has all turned round and GQ's success has been hugely responsible."
Obituary, page 12