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

Peng, one of China's biggest sport stars, said on social media earlier 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 roughly a half hour later and she had not been seen publicly or made a statement since then, alarming the global tennis community.

On Twitter on Wednesday, Chinese state-affiliated 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.

"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 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."

China's Ministry of Foreign Affairs did not immediately respond to a request for comment sent outside working hours.

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 as of Thursday morning had reported the letter.

The WTA and the ATP previously called for China to investigate Peng's allegations.

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