Peng Shuai is a former world number one doubles player and reached 14th in the singles rankings in 2011Chinese player Peng Shuai deserves "to be heard, not censored" after publicly accusing the country's former vice-premier of sexual assault, says the Women's Tennis Association.
In a post on Chinese social media site Weibo, Peng said she was "forced" into a sexual relationship with Zhang Gaoli.
"The events concerning Peng Shuai are of deep concern," said the WTA.
"The allegations must be investigated fully, fairly, transparently and without censorship."
Peng, 35, is a former world number one doubles player who has won two Grand Slam titles - at Wimbledon in 2013 and the 2014 French Open, both alongside Taiwan's Hsieh Su-wei.
She also achieved a career-high singles rankings of 14 in 2011 and reached the US Open singles semi-finals in 2014.
Peng's allegations were made earlier this month and soon deleted from China's internet. It is the first time such a claim has been made against one of China's senior political leaders.
Zhang, 75, has not responded to her claims.
He served as China's vice-premier between 2013 and 2018 and was a close ally of President Xi Jinping.
Peng acknowledged that she would not be able to provide proof to back up her claims.
"As an organisation dedicated to women, we remain committed to the principles we were founded on - equality, opportunity and respect," said WTA chief executive Steve Simon.
"Peng Shuai, and all women, deserve to be heard, not censored. Her accusation about the conduct of a former Chinese leader involving a sexual assault must be treated with the utmost seriousness.
"In all societies, the behaviour that she alleges took place needs to be investigated, not condoned or ignored.
"We commend Peng Shuai for her remarkable courage and strength in coming forward. Women around the world are finding their voices so injustices can be corrected.
"Our absolute and unwavering priority is the health and safety of our players. We are speaking out so justice can be done."
