Irvine Welsh was given drugs by fans at book readings after his first novel Trainspotting was turned into a feature film.

The author's cult novel, following the antics of a group Scottish drug addicts, was adapted into a movie starring Ewan MCGregor in 1996.

Following the release of the film, Welsh's fanbase grew and he began witnessing a bizarre phenomenon where admirers would show up at book shop appearances and offer him narcotics.

He tells Britain's The Times Magazine, "After Trainspotting, fans used to slip me drugs at book readings. I guess they wanted to get f**ked up with someone they perceived to be a celebrity to validate their lives."

Welsh, a former drug addict, claims he never took any of their substances, adding, "What are you going to do with a big pile of drugs if you're staying in a hotel room by yourself? Take a bunch and hit your head against the wall? No, you flush it down the toilet. They don't do it any more. I'm glad they've stopped."