Record-breaking US Olympic swimmer Michael Phelps has issued an apology after a British newspaper published a photograph purportedly showing him smoking marijuana.

Phelps promised in his statement there would be no repeat of his behavior. The News of the World said the picture was taken during a November house party while Phelps was visiting the University of South Carolina.

US anti-doping officials said the news was disappointing But they stressed that smoking marijuana out of competition was not an anti-doping matter at this point.

The US Olympic Committee and USA Swimming also expressed disappointment.