The European Union demanded on Tuesday China release “verifiable proof” of the safety of tennis player Peng Shuai, who disappeared earlier this month.

The EU is seeking evidence that Peng, a three-time Olympian and former top-ranked doubles player, is safe after she disappeared from the public eye earlier this month. The tennis star went missing after she accused a former Communist Party official, Zhang Gaoli, of sexual assault, and there has been little evidence to point to her well-being since.