World tennis champion Naomi Osaka has become the latest athlete to voice concerns over the whereabouts of Chinese tennis player Peng Shuai.

One of China's biggest sporting stars, Ms Peng has not been heard from since she made sexual assault allegations against a top Chinese official.

The Women's Tennis Association (WTA) said it had confirmed that she is "safe and not under any physical threat".

However, they were not able to directly reach her.

"I was recently informed of a fellow tennis player that has gone missing shortly after revealing that she has been sexually abused," Ms Osaka tweeted, using the hashtag #WhereisPengShuai.

"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."

It comes as a number of tennis players have spoken up about Ms Peng.

Earlier this week, world number one tennis player Novak Djokovic said he hoped she would okay, adding that he was shocked.

French player Nicholas Mahut also weighed in, saying "we are all concerned".

Ms Peng - a former number one ranked tennis doubles player- had posted about the alleged assault against Vice Premier Zhang Gaoli on Chinese social media site Weibo in November.

In the post, she said she was "forced" into a sexual relationship with Mr Zhang.

Mr Zhang, 75, served as China's Vice Premier between 2013 and 2018 and was a close ally of Chinese President Xi Jinping. He has not responded to her claims.

Her post was later taken down from the site and all mention of her on social media have been scrubbed.

Ms Peng has also not been seen or heard of publicly since.

Chief Executive of the WTA Steve Simon had earlier called on Chinese authorities to conduct "a full and transparent investigation" into Ms Peng's allegations involving sexual assault.

"We commend Peng Shuai for her remarkable courage... women around the world are finding their voices so injustices can be corrected."

Mr Simon said the WTA had received confirmation from several sources, including the Chinese Tennis Association that Ms Peng was safe, but added that he had not been able to reach her directly.

"My understand is that she is in Beijing in China, but I can't confirm that because I haven't spoken directly with her," Mr Simon told news outlet The New York Times.

Ms Peng's allegation is the highest profile case in China's #MeToo movement, which has mostly been going under the radar.