Peng Shuai, who was once the No.1 tennis doubles player in the world, and is one of China's biggest athletes, has publicly accused a former Chinese vice premier of forcing her into sex several years ago.
In a social media post that was later deleted, Peng said Zhang Gaoli, who became a member of the Politburo Standing Committee - China's top decision-making body - coerced her into sex and they later had an on-off consensual relationship.
That was according to a screenshot of her verified Weibo account late on Tuesday, which was deleted about half an hour after it was published.
But searches for Peng's name surged, and screenshots were shared in private messaging.
China's internet is heavily censored and the private lives of top leaders are a highly sensitive subject.
Peng, who said in the post that she could provide no evidence to back her allegations, did not respond to a request for comment, nor did China's State Council Information Office, which was also asked for comment from Zhang.
Sexual harassment and assault were rarely broached in China before the #MeToo movement, which became big in China in 2018, when a Beijing college student publicly accused her professor of sexual harassment. That spread to non-government organizations, media and other industries.
Peng was the world No.1 doubles player in 2014, the first Chinese player to achieve a top ranking, after winning the doubles titles at Wimbledon in 2013 and the French Open in 2014.