The head of the Women's Tennis Association says it's of "great concern" they've not been able to contact a missing top Chinese player.

Last month, former Wimbledon doubles champion Peng Shuai made sexual assault allegations against a former senior government official.

Chinese state media's released an email claiming to be from the 35-year-old.

But W-T-A chairman, Steve Simon, has told NBC News, he's not convinced.