The head of the Women’s Tennis Association on Wednesday voiced doubt over an email it received, also released by a Chinese state media outlet, in which tennis player Peng Shuai was said to deny her allegations of sexual assault.

Peng, one of China’s biggest sport stars, said on social media this month that former Chinese vice premier Zhang Gaoli coerced her into sex and that they later had an on-off consensual relationship.

Her post was deleted about half an hour later and she had not since then been seen in public or made a statement, alarming the global tennis community.

On Twitter on Wednesday, Chinese state media outlet CGTN released what it said was an email Peng had sent to WTA Chairman Steve Simon, who is also its CEO, in which she said the allegation of assault was untrue. Twitter is blocked in China.

“The statement released today (Wednesday) by Chinese state media concerning Peng Shuai only raises my concerns as to her safety and whereabouts,” Simon said in a written statement.

“I have a hard time believing that Peng Shuai actually wrote the email we received or believes what is being attributed to her.”

The statement comes as China prepares to host the Winter Olympics in Beijing in February. “My answer is very simple. This is not a foreign affairs matter, and I am not aware of the situation you mentioned,” foreign ministry spokesman Zhao Lijian said on Thursday when asked about Peng’s whereabouts.

The email which CGTN attributes to Peng says: “I’m not missing, nor am I unsafe. I’ve just been resting at home and everything is fine.”

Besides CGTN, the English-language arm of state broadcaster CCTV, no other Chinese media outlet had reported the letter.

ITF support

The International Tennis Federation (ITF) supports an investigation into the whereabouts of Peng, the governing body said on Thursday. “Player safety is always our top priority and we support a full and transparent investigation into this matter,” the ITF said in a statement.