In a stern ultimatum, the Women's Tennis Association (WTA) has threatened to pull tournaments from China unless satisfactory evidence of missing player Peng Shuai's safety is issued soon. 

The sport's governing body has been unable to contact for nearly two weeks since she accused a politician with the ruling Communist party of sexual assault. 

Top players, including men's world No. 1 Novak Djokovic, have expressed fears for the safety of Peng because the former Wimbledon and French Open doubles champion has been unreachable since making alarming allegations against China's former vice-premier Zhang Gaoli. 

On Thursday morning (AEDT), Chinese state media reported Peng had sent the WTA an email allaying any concerns about her wellbeing. The email, purportedly written by Peng herself, read: "Hello everyone this is Peng Shuai. 

"Regarding the recent news released on the official website of the WTA, the content has not been confirmed or verified by myself and it was released without my consent. 

"The news in that release, including the allegation of sexual assault, is not true. I'm not missing, nor am I unsafe. I've just been resting at home and everything is fine. Thank you again for caring about me. 

"If the WTA publishes any more news about me, please verify it with me, and release it with my consent. As a professional tennis player, I thank you all for your companionship and consideration. 

"I hope to promote Chinese tennis with you all if I have the chance in the future. I hope Chinese tennis will become better and better. 

"Once again, thank you for your consideration." 

The email was met with widespread scepticism among members of the tennis media. Nobody actually believed it was written by Peng. 

Soon after the email was made public, WTA chief Steve Simon released a statement in response, saying he too did not believe Peng sent that correspondence herself. 

Now Simon has gone a step further, issuing an ultimatum to China and threatening to cancel tournaments scheduled to take place in the country if "verifiable proof" of Peng's safety is not provided soon. 

"If at the end of the day we don't see the appropriate results from this, we would be prepared to take that step and not operate our business in China, if that's what it came to," Simon told the New York Times. 

"Should we find that what we are asking for cannot happen or will not happen, we are prepared to no longer do business within the region and move forward," he told TIME during the WTA tour finals in Mexico. 

The WTA is set stage 10 tournaments in China in 2022, including the prestigious season-ending tour finals in Shenzhen, which Australian Ash Barty won there in 2019. 

Simon was clearly concerned by the events concerning Peng's disappearance and cast serious doubts over the credibility of the email supposedly written by her. 

"The statement released today by Chinese state media concerning Peng Shuai only raises my concerns as to her safety and whereabouts," Simon said. 

"I have a hard time believing that Peng Shuai actually wrote the email we received or believes what is being attributed to her. Peng Shuai displayed incredible courage in describing an allegation of sexual assault against a former top official in the Chinese government. 

"The WTA and the rest of the world need independent and verifiable proof that she is safe. I have repeatedly tried to reach her via numerous forms of communication, to no avail. 

"Peng Shuai must be allowed to speak freely, without coercion or intimidation from any source. Her allegation of sexual assault must be respected, investigated with full transparency and without censorship. 

"The voices of women need to be heard and respected, not censored nor dictated to." 

Tennis praised for hitting back over 'fake' email 

Simon and the WTA have been praised for standing up to China, despite the potential ramifications of doing so to an economic superpower. 

Ex-Socceroo Craig Foster tweeted: "Extremely worrying story. Outstanding from @WTA Chair, Steve Simon. 

"Strong, not captured by the economic weight of China as most sports are, protective of the basic rights & wellbeing of an athlete with no compromise. Should be the norm. 

"Hoping for successful outcome, Steve." 

Tennis commentator David Law wrote: "Can't think of many (any?) examples of a sports leader ignoring financial/relationship repercussions in order to talk bluntly and honestly about the most important of issues, rather than hedging with management speak. Good for him." 

Journalist Luca Jacobs added: "WTA is not holding back, given how fake that previous statement by CCP media seemed."