Concerns have grown across the tennis community about the whereabouts of Chinese tennis star Peng Shuai.
Peng hasn't been seen in public since she accused former Chinese Vice Premier Zhang Gaoli of sexually assaulting her.
The 2013 Wimbledon doubles champion took to social media on November 2 to report that Gaoli had forced her to have sex with him when she visited him and his wife at their home for dinner approximately three years ago, despite repeated refusal.
The 35-year-old added that she later agreed to a secret affair with Zhang, who is reportedly 74 or 75 years old.
The post was quickly taken down from Chinese social media, but not before thousands of screenshots were redistributed online.
The Chinese Foreign Ministry's spokesperson commented on the lack of answer from the government saying her disappearance was "not a diplomatic matter" and he "was not aware of the situation".
Doubts over email purportedly from Peng
WTA chairman and CEO Steve Simon said in a statement on Wednesday that he doubts a recent email he received from missing Chinese tennis player Peng Shuai is actually from her.
On Wednesday, CGTN, the international section of China's state-owned media, released on its Twitter feed an email that it claimed was written by Peng and had been sent to Simon.
In the email, Peng says she's "resting at home" and recants her earlier accusation of sexual assault against Zhang.
But in his statement, Simon said he had a "hard time believing" the email is legitimate and called for Peng to be allowed to "speak freely, without coersion or intimidation".
Earlier, the Association of Tennis Professionals (ATP) said it was "deeply concerned" over Peng Shuai's immediate safety and whereabouts.
"We are encouraged by the recent assurances received by WTA that she is safe and accounted for and will continue to monitor the situation closely. Separately, we stand in full support of WTA’s call for a full, fair and transparent investigation into allegations of sexual assault carried out against Peng Shuai," said ATP chairman Andrea Gaudenzi.
Players express concern
World No.1 Novak Djokovic said at the ATP Finals: "Honestly, it's shocking that she's missing, more so that it's someone that I have seen on the tour in the previous years quite a few times. It's not much more to say than hope that she will be found, that she's OK. It's just terrible. I can imagine just how her family feels that she's missing."
Former women's tennis stars Chris Evert and Billie Jean King also expressed concern. French tennis player Alize Cornet also took to social media saying "Let's not remain silent".
"Censorship is never ok at any cost, I hope Peng Shuai and her family are safe and ok. I'm in shock of the current situation and I'm sending love and light her way," Naomi Osaka tweeted.
On Thursday, tennis superstar Serena Williams was the latest to join her peers by tweeting that she was "devastated and shocked" to hear about Shuai's disappearance.
"I hope she is safe and found as soon as possible. This must be investigated and we must not stay silent," Williams went on.
In a statement, the Women's Tennis Association (WTA) praised Shuai for "her remarkable courage and strength" saying "women around the world are finding their voices so injustices can be corrected."
CEO Steve Simon also added that the WTA would "full, fair and transparent investigation into sexual assault allegations against former Chinese leader and also calls for end of censorship against Peng Shuai."
The organisation has also called on China to uncover Shuai's whereabouts.