Four-time grand slam winner Naomi Osaka said she was concerned over the whereabouts of fellow tennis player Peng Shuai, who has not been heard from since making allegations of sexual assault against a former Chinese vice premier.

Peng, one of China’s biggest sport stars, said on social media earlier this month that a former member of China’s Politburo Standing Committee, Zhang Gaoli, coerced her into sex and that they later had an on-off consensual relationship.

Peng’s post went viral on Chinese social media, despite it being taken down by censors within minutes. Subsequent posts and reactions, even keywords such as “tennis”, also appeared to be blocked, and numerous references to Peng were scrubbed from China’s internet.

The global tennis community has grown alarmed as Peng has not been seen since the post and on Monday the governing body of men’s tennis (ATP) backed the Women’s Tennis Association’s (WTA) call for China to investigate the allegations.

“I was recently informed of a fellow tennis player that has gone missing shortly after revealing that she has been sexually abused,” said Japan’s Osaka. “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. #whereispengshuai.”

WTA chief Simon told the New York Times on Sunday that no one at the Tour has talked directly to Peng but that he had received assurances from the Chinese Tennis Association that she was safe “and not under any physical threat”.

The Chinese Tennis Association did not respond to a request for comment on Wednesday.

The 35-year-old Peng was the first Chinese player to top the world rankings when she was doubles No. 1 in 2014. She won doubles titles at Wimbledon in 2013 and the French Open in 2014.

Zhang, now 75, was a vice premier between 2013 and 2018 and served on the Politburo Standing Committee between 2012 and 2017.

Peng’s Weibo account is active, but has no mention of Zhang and comments appear to have been disabled.