Phelps concedes 'mistake,' says he's sorry

COLORADO SPRINGS, Feb. 1 (UPI) -- U.S. Olympic swimmer Michael Phelps has apologized after a photograph appeared in a British tabloid showing him smoking marijuana.

Phelps has won 14 career Olympic medals, and holds the record for the most gold medals won at a single Summer Games -- eight last year in Beijing.

The picture in the News of the World purported to show Phelps smoking marijuana from a pipe during a University of South Carolina party last year.

Phelps released a statement saying, "I engaged in behavior which was regrettable and demonstrated bad judgment. I'm 23 years old, and despite the successes I have had in the pool, I acted in a youthful and inappropriate way, not in a manner that people have come to expect from me. For this, I am sorry. I promise my fans and the public -- it will not happen again."

Statements from USA Swimming and the U.S. Olympic Committee acknowledged Phelps made a mistake and apologized for his actions.