The head of the Women's Tennis Association has cast doubt on an email claiming to be from Chinese tennis star Peng Shuai, saying it only raises further concerns for her safety, CNN reported. China's state-owned television broadcaster CGTN released the email, purportedly from Peng, in the early hours of Wednesday morning local time, amid growing international concern for her whereabouts. The email — which has not been verified by CNN — claimed Peng is fine and appears to walk back her sexual allegations against a former top Communist Party leader. It was sent to the WTA Chairman and CEO Steve Simon, CGTN reported. Simon has said he doubts the email is authentic. "The statement released today by Chinese state media concerning Peng Shuai only raises my concerns as to her safety and whereabouts," Simon said in a statement, "I have a hard time believing that Peng Shuai actually wrote the email we received or believes what is being attributed to her." He added: "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." Several prominent voices have raised concern over Peng's whereabouts. One of China's most recognizable tennis stars, Peng has not been seen in public since she accused former Vice Premier Zhang Gaoli of coercing her into sex at his home three years ago, according to screenshots of a since-deleted social media post dated November 2. Her post on Weibo, China's Twitter-like platform, was deleted within 30 minutes of publication, with Chinese censors moving swiftly to wipe out any mention of the accusation online. Her Weibo account, which has more than half a million followers, is still blocked from searchers on the platform. Tennis superstar Naomi Osaka was among the latest top athletes to voice concern for Peng. "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," Osaka said as part of a Twitter statement on Tuesday. She included the hashtag #WhereIsPengShuai. Tennis legend and 39-time Grand Slam championship-winner Billie Jean King said on Twitter, "Hoping that Peng Shuai is found safe and that her accusations are fully investigated." And former world No.1 Chris Evert said, "these accusations are very disturbing." "I've known Peng since she was 14; we should all be concerned; this is serious; where is she? Is she safe? Any information would be appreciated," she said in a post on Twitter. On Sunday, the Women's Tennis Association (WTA) called on the Chinese government to investigate the allegations, insisting the former top-ranked doubles player should be "heard, not censored." Peng's purported email walking back the allegations was released by CGTN on Wednesday. The state media network did not provide any video or further evidence verifying Peng's whereabouts. It also didn't explain how it obtained the letter. The email reads: "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." "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," it continues. The ATP Tour, a worldwide top-tier tennis tour for men, had said in a statement Monday that it was "encouraged by the recent assurances received by WTA that (Peng) is safe and accounted for and will continue to monitor the situation closely," but did not provide any further details about the veracity of the assurances. "Separately, we stand in full support of WTA's call for a full, fair and transparent investigation into allegations of sexual assault against Peng Shuai," ATP Chairman Andrea Gaudenzi said in the statement. Peng's explosive #MeToo allegations against a former state leader have reverberated across the Chinese internet, despite authorities' attempts to to wipe out any mention of such a politically sensitive scandal. Zhang, 75, served on the ruling Communist Party's seven person Politiburo Standing Committee -- the country's supreme leadership body -- from 2012 to 2017 during Chinese leader Xi Jinping's first term in power. He retired as vice premier in 2018. In her post, which reads as an open letter to Zhang, the 35-year-old tennis star alleges a relationship over an intermittent period that spanned at least 10 years. "Why did you have to come back to me, took me to your home to force me to have sex with you?" she wrote. Peng said she did not have evidence to prove her allegations, and claimed Zhang was always worried that she would record things. "I couldn't describe how disgusted I was, and how many times I asked myself am I still a human? I feel like a walking corpse," wrote Peng. CNN cannot independently verify Peng's post, and has reached out to both her and China's State Council, which handles press inquiries for the central government, for comment. On Wednesday, China evaded questions from the media about Peng's allegations against Zhang. Chinese MOFA spokesperson Zhao Lijian suggested reporters should reach out to the "competent department," despite reporters remarking on the lack of response from the Ministry of Public Security. Speaking at a press conference, Zhao was asked about the WTA's concerns over Peng's "safety and whereabouts" and if the government planned on taking any action, to which Zhao said the issue "wasn't a diplomatic matter," declining to comment any further. Reporters in the room continued to press on the subject, claiming they had reached out to the Ministry of Public Security for comment, but had not heard back, which resulted in questions about which department journalists should reach out to for more details. "Do you think the Foreign Ministry spokesperson is omnipotent?" Zhao replied. "You should go ask competent department," Zhao added, once again avoiding the reporter's question.