Plus-sized dominatrix claims Michael Phelps paid her to urinate on him

A plus-sized dominatrix has claimed that she urinated on American swimming great Michael Phelps in exchange for money, adding another chapter to the Olympian's sexual escapades.

Kim Petro, a 36-year-old from New York, has revealed details of a night she spent with the former swimmer, during which she claims that he sported women's underwear.

Petro has revealed that Phelps got in touch with her in 2013 to arrange the meeting at the London Hotel in New York and paid her 900 dollars, adding that when he said drink some water before she got to the hotel, she claimed that knew what she was in for, News.com.au reported.

Petro said that she was going to go to the bathroom anyway, insisting that she figured she might as well get paid for it.

Petro further said that after she was done, Phelps asked if it was okay to pleasure himself, insisting that she told him of course she was going to bend the rules a little for a famous Olympian, so he pulled down his panties.

Petro's claims come just a couple of months after Phelps proposed to his now fiancee and former Miss California, Nicole Johnson, the report added.