(Fred Lee/Getty Images)

The WTA continues to express concern for Peng Shuai, despite the missing tennis star reemerging in public at a youth tennis tournament in Beijing on Sunday.

Photos from the event were published by the organizer, while state-run media shared video of Peng at the tournament and a restaurant. Steve Simon, chairman and CEO of the WTA, called the video “insufficient.”

Until Sunday, Peng had not been seen in public since posting a video to the Chinese social media platform Weibo on Nov. 2, detailing allegations of sexual abuse by former vice premier Zhang Gaoli. The post was taken down minutes after it was posted, and any mention of Peng’s claims has been scrubbed as well.

“While it is positive to see her, it remains unclear if she is free and able to make decisions and take actions on her own, without coercion or external interference,” said Simon.

The WTA head’s latest remarks come after he sent a letter to the Chinese Ambassador to the United States asking for confirmation that Peng is safe and for a full, uncensored investigation into her allegations.

In the letter, Simon also referenced the WTA’s tenuous relationship with China, saying if the stated requests weren’t met, “we will have no choice but to seriously consider whether we can play in China again.”

Simon ended the correspondence by saying the “WTA is at a crossroads with China.”

Tennis stars have also spoken out about the Peng situation, with Serena Williams writing via social media post, “This must be investigated and we must not stay silent.” Naomi Osaka also commented on Peng’s disappearance, saying, “Censorship is never ok at any cost, I hope Peng Shuai and her family are safe and ok.”