China kept silent Monday over growing concern for tennis star Peng Shuai, who has not been heard from since accusing a powerful politician of sexual assault -- the first time the #MeToo movement has struck at the top echelons of the ruling Communist Party.
The Women's Tennis Association (WTA) called Sunday for Peng's claims to be "investigated fully, fairly, transparently and without censorship", and current and former players, including men's world number one Novak Djokovic, have expressed fear for the safety of the former Wimbledon and French Open doubles champion.
Asked to respond to the mounting questions, foreign ministry spokesman Zhao Lijian said: "I have not heard of the issue you raised."
He added that "this is not a diplomatic question" and made no further comment on the fate of the former world number one doubles player.
Details of Peng's reported accusations, made earlier this month that former vice-premier Zhang Gaoli had sexually assaulted her, remain scrubbed from China's Internet. Searches for their names on key portals come back empty.
Searches for her account on China's Twitter-like Weibo platform also returned no results, although the account was still accessible via a direct web link.
China's national tennis association did not respond to AFP requests for comment.
In its statement, the WTA's chairman Steve Simon said the events concerning Peng were "of deep concern" and called for her claims to be "treated with the utmost seriousness".
"Our absolute and unwavering priority is the health and safety of our players. We are speaking out so justice can be done," the statement said.
Separately, Simon told the New York Times: "We've received confirmation from several sources, including the Chinese Tennis Association, that she is safe and not under any physical threat."
- 'Shocking' -
Men's number one Djokovic, speaking after his ATP Tour Finals match against Casper Ruud on Monday, described the situation as "terrible".
"Honestly it's shocking that she's missing," said the Serb.
"More so that it's someone that I've seen on the tour in previous years quite a few times.
"There's not much more to say than to hope that she's ok and it's just terrible... I can imagine how her family feels, you know, that she's missing."
Chris Evert, the 18-time Grand Slam winner, on Sunday became the highest profile current or former female player to join social media expressions of concern that have given rise to the Twitter hashtag #WhereIsPengShuai.
Evert called the situation "very disturbing".
"I've known Peng since she was 14; we should all be concerned; this is serious; where is she? Is she safe? Any information would be appreciated," Evert tweeted.
Earlier this month, Peng, 35, reportedly wrote on social media that Zhang -- who is in his seventies -- "forced" her into sex and said they had an on-off relationship lasting several years.
The Weibo post appeared to have been deleted quickly and AFP was unable to verify the authenticity of screenshots containing the allegation or substantiate the claims made in them.
China's online censors moved rapidly to erase evidence of the reported allegations and Peng has not been heard from since.