WTA chief executive, Steve Simon, says the latest proof of Chinese tennis player Peng Shuai’s whereabouts is ‘insufficient’ evidence of her safety.Peng has not been in direct contact with the WTA since accusing former Vice Premier, Zhang Gaoli, of sexual assault two weeks ago.On Saturday night, Chinese state-affiliated media posted two clips on Twitter of Peng allegedly having dinner with companions in a restaurant. A third video, posted today, also claims to show her at a tennis tournament in Beijing.This follows an email they shared earlier this week, purportedly from Peng, claiming she was safe and well.However, doubts have been cast over the authenticity of this ‘proof.’ BBC China media analyst, Kerry Allen said a date appeared to have been blurred out the latest video, despite claims the video was shot on Saturday, Beijing time.ENTER GIVEAWAY"While it is positive to see her, it remains unclear if she is free and able to make decisions and take actions on her own, without coercion or external interference," said Simon.The WTA chief has also written to the Chinese Ambassador to the United States, Qin Gang, imploring him to discuss the “urgent issue” with high-ranking Chinese government officials, so the situation can be resolved.“Peng Shuai has been missing for more than two weeks and we are deeply worried about her health and safety,” he wrote. “Nothing is more important to the WTA than the well-being of our players. It is my top priority.”"Simply put, the WTA is at a crossroads in China. I hope I can rely on you to convey these messages to the leadership in China so this issue can be resolved.”

Simon specified two requests to Qin, for which he sought the ambassador’s assistance.

The first –– that there is “independent and verifiable” confirmation that Peng is safe. And the second –– that the allegation of sexual assault is “investigated fairly, fully, transparently and without censorship.”

Meanwhile, a number of tennis stars have shared the hashtag ‘#WhereIsPengShuai’ on social media and expressed concerns for her safety.

Roger Federer and Rafael Nadal are the latest to join calls for her whereabouts.

“I follow the news and read the articles about Peng Shuai,” Nadal told L’Equipe on Saturday. “Even though I don’t have all the information, the most important thing is that she is okay. All of us in the tennis family hope to see her back with us soon.”

In a separate interview with Sky Italy, Federer stated: “The tennis tour is my second family. I have been on the pro tour for 20-25 years so I am connected to every ATP and WTA player.”