U.S. Ski and Snowboard Association President Bill Marolt said Lago left Vancouver, British Columbia, Friday after photos surfaced in the media that showed the 22-year-old athlete hanging his bronze medal over his groin area, People.com reported Saturday.
Another photo reportedly shows a woman kissing the medal on a public street.
The photos were taken Thursday, one day after Lago captured the medal in the men's halfpipe snowboarding competition.
"Scotty Lago is a great athlete but with that comes a responsibility of proper conduct and his involvement in this situation is not acceptable," Marolt said in a statement. "Scotty realizes his conduct was inappropriate. He has formally apologized and also made a decision to leave Vancouver today."
Sources close to Lago told TMZ.com the athlete would have been asked to leave the Winter Olympics by the U.S. Olympic Committee had he not voluntarily departed.