Paul Hunter was yesterday fined £4,550 after testing positive for marijuana at the grand prix at Bournemouth last October.
The 19-year-old from Leeds must merely give up his prize money for reaching the last 16, but the loss of the accompanying 1,140 ranking points drops him from 19th to 24th in the world. He won his first world-ranking event, the Regal Welsh Open, in January.
Hunter also appeared before the disciplinary committee in January 1996. He was fined £2,500 then (£2,000 suspended for 12 months) after streaking six months earlier at the Blackpool qualifying school.
Hunter has failed to qualify for the Embassy World Championship, which starts in Sheffield on Saturday, and his last playing appearance came in Plymouth recently, when he lost in the first round of the British Open.
Hunter's manager, Geoff Feint, said of the punishment: "I feel it's a satisfactory outcome. The incident occurred prior to him joining us and we will be standing by him.
"His professional behaviour has been impeccable and we sincerely hope the episode is a one-off."
Ian Doyle, a vociferous recent critic of the WPBSA, backed snooker's governing body this time.
"For once I believe the WPBSA have got it right," he said. "I hope it's a stern warning to Paul, because I'd hate to see a promising career ruined. Paul should take a long look at himself in the mirror."
Two other players were punished by the World Professional Billiards and Snooker Association (WPBSA) disciplinary committee in Bristol yesterday. Chris Scanlon was fined the £195 and 400 ranking points he earned in the International Open in 1994 after also testing positive for marijuana six months earlier.
Stephen Ormerod, the world number 308, was fined £800 with £200 costs for testing positive last October for marijuana and norandosterone; the 21-year-old has no prize money to his name.
Peter Gilchrist, the world billiards number three and chairman of the WPBSA's billiards committee, was fined £100 with £150 costs for taking a cold cure which included ephedrine. Gilchrist also tested positive on October 29th - after playing Ormerod in the satellite event in Malvern.