Ross Rebagliati (b. July 14, 1971)
Canadian Ross Rebagliati won the first-ever Olympic gold medal in Snowboarding in 1998, but was almost stripped of his medal after testing positive for marijuana after the race. Rebagliati admitted that he had smoked marijuana in the past, but said the positive test was the result of accidently inhaing nearby marijuana smoke at a going away party in his hometown of Whistler, BC. The Olympic committee allowed Rebagliati to keep his medal.
Source: Mike Downey, Rebagliati Gets to Keep Gold Medal, Los Angeles Times, 2/13/98