Martina Navratilova has voiced her anger after activists wearing "Where is Peng Shuai?" T-shirts at Wimbledon accused security personnel of warning them against "political" messaging.
A group of four men representing the Free Tibet human rights organisation were challenged by security while walking around the All England Club grounds wearing the shirts.
They claim they were stopped and searched and told not to approach other spectators about Chinese tennis player Peng, with security adding that if there were more of them it would be a "problem".
"We were peacefully walking around the grounds, occasionally talking to people about Peng Shuai," Free Tibet representative Will Hoyles told Telegraph Sport.
"We were getting huge support from people around the grounds. At one point security staff started questioning us and when we said we were just talking to people she told us not to approach people and that Wimbledon wants to remain politically neutral.
"Peng Shuai is still not free and WTA agrees. Wimbledon should be speaking out for her release and not trying to stop tennis fans discussing human rights."
A video the activists posted to Twitter received a retweet from nine-time champion Martina Navratilova, where she said: "What? Not allowed to speak?!? WTH [what the hell]?"
An All England Club spokesperson said: "We can confirm that four guests were approached today by security whilst walking outside No 1 Court. These individuals are now enjoying their day with us and continue to be able to wear their T-shirts. Like much of the tennis community and people around the world more broadly, we remain very concerned for Peng Shuai and we continue to support the WTA's efforts."
What? Not allowed to speak?!? WTH? https://t.co/RRsTVhHMWd
— Martina Navratilova (@Martina) July 4, 2022
Former world No 1 doubles player Peng disappeared from public view for weeks late last year, after appearing to allege a former senior Communist Party official had pressured her into sex.
Despite making appearances at the Beijing Winter Olympics in February and retracting her comments in public, there remain fears over her ability to act and speak freely. The WTA has suspended hosting events in China over their concerns.
There was similar controversy at the Australian Open in January. Tennis Australia officials came under fire from Navratilova, who called them "cowardly" and suggested they were putting sponsorship money ahead of human rights when spectators wearing "Where is Peng Shuai?" T-shirts were told to remove them by security.
The TA later backtracked, saying the fans could wear the T-shirts but were not permitted to disrupt the event for others.