Updated (11:34 p.m.)—The greatest Olympic champion in history is $100,000 richer today from a win outside the pool, according to one celebrity gossip website.
Phelps reportedly spent some of the winnings at an area nightclub.
But in a message on his Twitter account, Phelps cast doubt on the report.
"I wish I won a 100k.... Haha not true tho:(," Phelps wrote on the social media site.
Last month, that friends of the swimmer expressed concern over the his interest in high-stakes card games.