Transgender US swimmer Lia Thomas taking legal action to compete again

American swimmer Lia Thomas, who gained worldwide fame by becoming the first transgender athlete to win an NCAA college title, is taking legal action in an effort to return to elite female sports – including the Olympics.

Thomas has not swum since World Aquatics introduced new rules in 2022, which ban anyone who has undergone “any part of male puberty” from the female category. Before then, transgender women could compete if they lowered their testosterone levels.

In a scientific policy document that informed the decision, World Aquatics said swimmers like Thomas maintained significant physical benefits – in endurance, strength, speed, power and lung size – from undergoing male puberty, even after lowering their testosterone levels through medication.

Thomas, who was a moderate swimmer in the men’s category before his switch, has now recruited Canadian law firm Tyr to take a case to the sport’s arbitration court in Switzerland. However, as the 25-year-old is not currently registered with US swimming, it is understood the case is highly unlikely to be heard before the Paris Olympics.

The movement, revealed by the Daily Telegraphis the latest twist in the vexed debate between those who argue that fairness and safety in women’s sports are paramount, and others who argue that the inclusion of transgender athletes should be a priority.

Thomas has always denied that he made a move to get ahead. “The biggest misconception, I think, is the reason I switched,” Thomas said in 2022. “People will say, ‘Oh, she just switched so she could have an advantage, so she could win.’ I switched to be happy, to be true to myself.”

In a statement on Thursday, World Aquatics executive director Brent Nowicki defended the gender inclusion policy, saying it was “rigorously developed based on advice from leading medical and legal experts, and in careful consultation with athletes.”

“World Aquatics remains confident that its gender inclusion policy represents a fair approach and remains absolutely committed to protecting women’s sport,” he added.

Thomas would not comment yet, but what happens next will be closely watched by other governing bodies. In recent years, rugby, athletics and cycling were among the sports where rules became stricter, and a win for Thomas would open them up to legal challenges.