We would stress that it is important to know where she is and know her state, know about her wellbeing," Throssell said.

The head of the Women's Tennis Association (WTA) Steve Simon has said he is willing to lose hundreds of millions of dollars worth of business in China if Peng is not fully accounted for and her allegations are not properly investigated.

Perceived criticisms of China, which is also due to host the 2022 Winter Olympics in February, have previously resulted in significant public and political backlash, as well as loss of access.

'Staged statement of some type'

Simon said the WTA had been in conversation with counterparts at the Chinese Tennis Association, who had provided assurances Peng was unharmed in Beijing.

"There's so many digital approaches to contact people these days that we have, and to date we still have not been able to get a response."

Earlier this week, Chinese state media released an email, purportedly sent to Simon from Peng, walking back her allegations and claiming she is fine.

The alleged email was released only on English-language platforms and domestic Chinese media have not reported on its contents, despite Peng being a household name in China.

When asked about the email, Simon questioned its veracity, describing it as a "staged statement of some type," noting he had yet to receive a follow-up reply, despite responding immediately.

"But at this point I don't think there's any validity in it and we won't be comfortable until we have a chance to speak with her," he added.

Later on Friday, CGTN journalist Shen Shiwei tweeted three photos he claimed Peng had posted on WeChat along with the message "happy weekend."

Shen said the photos were shared by one of Peng's friends.

CNN could not independently verify when the photos were taken, whether Peng posted the photos herself, or whether they were posted at all.

In a Twitter post on Saturday, Hu Xijin, editor of Chinese state-run tabloid the Global Times, republished the photos of Peng amid concerted efforts by government-controlled media to ease the intensifying concerns about the tennis star's whereabouts and welfare.

"I confirmed through my own sources today that these photos are indeed Peng Shuai's current state.

"She will show up in public and participate in some activities soon."

Chinese state media Twitter accounts have been increasingly posting anonymously sourced information about the tennis star, ostensibly aimed at quelling the controversy without even acknowledging her claim against Zhang.

All media organizations in China are strictly controlled by the country's propaganda authorities.