Billionaire Elon Musk took to Twitter late on Thursday to denounce as "utterly untrue" claims in a news report that he had sexually harassed a flight attendant on a private jet in 2016.

Business Insider reported earlier on Thursday that Musk's SpaceX paid $250,000 in 2018 to settle a sexual harassment claim from an unnamed private jet flight attendant who accused Musk of exposing himself to her.

The article quoted an anonymous person who said she was a friend of the flight attendant. The friend had provided a statement as part of the private settlement process, according to the article.

"I have a challenge to this liar who claims their friend saw me 'exposed' — describe [sic] just one thing, anything at all (scars, tattoos, …) that isn’t known by the public. She won’t be able to do so, because it never happened," Musk tweeted.

Reuters was not able to verify the Business Insider account. Musk and SpaceX did not respond to Reuters requests for comment on the Business Insider story or on Musk's tweets.

In addition to allegedly exposing himself, Musk rubbed the flight attendant's thigh and offered to buy her a horse if she would "do more" during an in-flight massage, Business Insider quoted the friend of the flight attendant as saying.

The flight attendant came to believe that her refusal to accept Musk's proposal had hurt her opportunities to work at SpaceX and prompted her to hire a lawyer in 2018, according to Business Insider.

The rocket company made the settlement out of court and included a nondisclosure agreement which prevented the flight attendant from speaking about it, Business Insider said. The news site did not name the friend or the flight attendant.