News of the World said the picture was taken during a November house party while Phelps was visiting the University of South Carolina. During that trip, he attended one of the school's football games and received a big ovation when he was introduced to the crowd.
While the newspaper did not specifically allege that Phelps was smoking pot, it did say the pipe is generally used for that purpose and anonymously quoted a partygoer who said the Olympic champion was "out of control from the moment he got there."
"He grabbed the bong and a lighter and knew exactly what to do," a witness said of the swimming superstar, according to the News of the World report.
"He looked just as natural with a bong in his hands as he does swimming in the pool. He was the gold medal winner of bong hits."
"I engaged in behavior which was regrettable and demonstrated bad judgment," Phelps said in the statement released by one of his agents. "I'm 23 years old and despite the successes I've had in the pool, I acted in a youthful and inappropriate way, not in a manner people have come to expect from me. For this, I am sorry. I promise my fans and the public it will not happen again."
This isn't the first embarrassing episode for Phelps after an Olympic triumph. In 2004, a few months after winning six gold and two bronze medals in Athens, the swimmer was arrested on a drunken driving charge at age 19. He pleaded guilty and apologized for the mistake.
