Serena Williams has called for an investigation into a Chinesetennis player who went missing.Peng Shuai has not been seen in public since accusing China's former vice premier of sexual assault.
Serena Williams has added her voice to a growing number of stars from the world of tennis expressing their concerns over the safety of Chinese player Peng Shuai.
All mention of her accusation has also been scrubbed from Chinese social media platforms like Weibo.
Doubts were immediately cast about the letter's authenticity after it appeared only on the Twitter timeline of CGTN, an English language TV channel run by the Chinese state.
Steve Simon, the head of the WTA, $4
Peng's disappearance has sparked outrage in the sport, with Williams on Thursday joining fellow stars like Novak Djokovic and Naomi Osaka in speaking out about Peng, and calling for an investigation into her whereabouts.
23-time Grand Slam winner Williams said the case "must be investigated" and urged people to "not stay silent."
Williams tweeted a picture of Peng with the hashtag #WhereIsPengShuai.
"I am devastated and shocked to hear about the news of my peer, Peng Shuai," Williams wrote.
"I hope she is safe and found as soon as possible. This must be investigated and we must not stay silent.
"Sending love to her and her family during this incredibly difficult time.
—Serena Williams (@serenawilliams) $4
Williams is one of many high profile athletes in the game raising concerns for Peng's safety.
Men's world number one Novak Djokovic said it was "shocking" that she was missing, and Naomi Osaka tweeted a picture of Peng saying "censorship is never OK"
—NaomiOsaka大坂なおみ (@naomiosaka) $4
Peng is one of China's most successful tennis players, having made a name for herself in doubles. She has won two Grand Slams, taking home the doubles competition at Wimbledon 2013 and the 2014 French Open, playing alongside Hsieh Su-wei.
In 2014, she was ranked number one in the world in doubles.