Outcry over Chinese tennis star Peng Shuai's whereabouts escalated as the Women's Tennis Association (WTA) threatened to pull tournaments out of China over her disappearance and the White House asked Beijing to prove she was safe.

Former doubles world number one Peng has not been seen or heard from publicly since she said on Chinese social media on Nov 2 that former vice-premier Zhang Gaoli coerced her into sex and they later had an on-off consensual relationship.

Neither Zhang nor the Chinese government has...