LAUSANNE, Switzerland -- Transgender swimmer Lia Thomas has asked a Swiss sports court to overturn rules imposed by World Aquatics that stop her from competing in elite women's races, saying they are discriminatory.
The Court of Arbitration for Sport said Friday it had registered Thomas' request, but no date for a hearing was decided. Confidentiality around a case that began in September was lifted after it was reported in British media.
"Ms Thomas seeks an order from the CAS declaring that the [World Aquatics rules] are unlawful, invalid, and of no force and effect," said the court based in the Olympic home city of Lausanne, Switzerland.
World Aquatics agreed on rules in June 2022 that banned transgender women who have been through male puberty from competing in women's races. It also created an "open" category for which transgender athletes would be eligible.
Other Olympic sports bodies, including track and field and cycling, have since adopted similar rules, which supporters say acknowledge physical advantages from male puberty that athletes retain long term after transitioning.
Swimming's rules were agreed to months after Thomas, then a student at the University of Pennsylvania, won a national college title in the 500-yard freestyle. Thomas' results in women's races exceeded her previous results in men's races.
Though the NCAA championships were held outside the World Aquatics system, Thomas said she hoped one day to compete in U.S. Olympic trials.
"Ms Thomas accepts that fair competition is a legitimate sporting objective and that some regulation of transgender women in swimming is appropriate," the Swiss court said.
"However, Ms Thomas submits that the [rules] are invalid and unlawful as they discriminate against her," CAS said, citing "the Olympic Charter, the World Aquatics Constitution, and Swiss law including the European Convention on Human Rights and the Convention on the Elimination of All Forms of Discrimination against Women."
Thomas argued that "such discrimination cannot be justified as necessary, reasonable, or proportionate to achieve a legitimate sporting objective," the court said.
CAS cases are typically heard by three judges -- selected by the rival parties and the court itself -- who could yet decline jurisdiction.