evidence: Transgender swimmer Lia Thomas has been quietly mounting a legal battle against World Aquatics to overturn the swimming governing body’s effective ban on most trans women competing in the highest levels of the sport, a lawyer representing Thomas confirmed to NBC News on Friday. Carlos Sayao, a partner at top Canadian law firm Tyr, said Thomas is asking the Court of Arbitration for Sport in Switzerland to overturn the new World Aquatics rules, issued in June 2022, that prohibit trans women from competing in women’s swimming events unless they transitioned before age 12. [...] "Ms Thomas accepts that fair competition is a legitimate sporting objective and that some regulation of transgender women in swimming is appropriate," the statement reads. "However, Ms Thomas submits that the Challenged Provisions are invalid and unlawful as they discriminate against her contrary to 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; and that such discrimination cannot be justified as necessary, reasonable, or proportionate to achieve a legitimate sporting objective."