American tennis great Serena Williams says the case of Chinese player Peng Shuai “must be investigated” and urged people “not to stay silent” about her welfare.
Peng, 35, has not been heard from since she made sexual assault allegations against a leading Chinese government official a fortnight ago.
Amid growing concerns over her whereabouts, Chinese state media has released an email attributed to Peng, albeit doubts remain over its authenticity.
“I hope she is safe and found as soon as possible,” Williams, 40, said.
Concern for Peng’s welfare has continued to grow since she said she was “forced” into a sexual relationship with former China vice-premier Zhang Gaoli.
The allegations were made in a post on Chinese social media site Weibo on 3 November and soon deleted from China’s internet.
It is the first time such a claim has been made against one of China’s senior political leaders.
Steve Simon, chairman of the Women’s Tennis Association, said Peng deserved “to be heard, not censored” on the allegations.
On Wednesday, he cast doubt on the email released by Chinese state media, saying it “only raises” concerns about Peng’s safety.
Williams is one of many leading players to speak out about Peng’s welfare, following men’s world number one Novak Djokovic and Japan’s four-time major winner Naomi Osaka.
“I am devastated and shocked to hear about the news,” said Williams, who is a 23-time Grand Slam singles champion.
“This must be investigated and we must not stay silent.
“Sending love to her and her family during this incredibly difficult time.”