Swimmer Michael Phelps, who has won more gold medals than anyone in Olympic history, admitted on Sunday that he had engaged in regrettable and inappropriate behavior after a photo of him smoking marijuana was published in a British tabloid over the weekend.

The 14-times Olympic gold medal winner issued a public apology soon after a photo pf him with a cannabis pipe was published in Britain's News of the World on late Saturday, January 31.

The tabloid says it was snapped at a party on November 6, 2008 while Phelps was visiting his alleged girlfriend Jordan Matthews at University of South Carolina who is currently studying there.

I engaged in behavior which was regrettable and demonstrated bad judgment, Phelps said in a statement released by Octagon, his management firm, and posted on his Facebook site.

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.

Click here to view the photo of Michael Phelps.

The United States Olympic Committee, which last week named Phelps its male athlete of the year, issued a statement saying it was disappointed in Phelps' behavior.

Michael has acknowledged that he made a mistake and apologized for his actions, it said. We are confident that, going forward, Michael will consistently set the type of example we all expect from a great Olympic champion.

Phelps was in Tampa, Fla., during Super Bowl week for promotional appearances for one of his sponsors. He was supposed to attend Sunday's game but later changed his plans.