The Women's Tennis Association has announced the immediate suspension of all tournaments in China amid concern for Chinese tennis player Peng Shuai.
Peng disappeared from public view for three weeks after accusing a top Chinese official of sexual assault.
WTA chief Steve Simon said he had "serious doubts" that Peng was "free, safe and not subject to intimidation".
"In good conscience, I don't see how I can ask our athletes to compete there," he said.
The WTA has repeatedly called for a full investigation into Peng's claims.
Peng was not seen in public for three weeks after she accused former Vice-Premier Zhang Gaoli of sexual assault.