Lia Thomas, a transgender swimmer who created controversy during the 2022 season with a win at the NCAA championships, lost a legal battle over rules that prevented trans swimmers who have been through male puberty from competing in elite women’s events.

The Court for Arbitration of Sport dismissed Thomas’ request for arbitration with World Aquatics, according to a ruling released Wednesday. The governing body in swimming made its ruling in 2022, which essentially banned transgender swimmers from competing in female events. World Aquatics also created an "open" category for transgender athletes.

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Lia Thomas prepares for race

Lia Thomas prepares to swim the women's 500-yard freestyle final at the NCAA swimming and diving championships. (AP Photo/John Bazemore)

Thomas asked the Switzerland-based court to overturn the rules, saying they were invalid, unlawful and discriminatory.

"The panel concludes that she lacks standing to challenge the policy and the operational requirements in the framework of the present proceeding," the court said in a ruling.

The three-judge panel said USA Swimming had no authority to "to modify such scope of application" of its rules.

"World Aquatics is dedicated to fostering an environment that promotes fairness, respect, and equal opportunities for athletes of all genders and we reaffirm this pledge," the organization said in a statement, via USA Today. "Our policies and practices are continuously evaluated to ensure they align with these core values, which led to the introduction of our open category. 

Pennsylvania's Lia Thomas

Lia Thomas of the University of Pennsylvania after winning the 500-yard freestyle final at the Ivy League women's swimming and diving championships at Harvard University, Feb. 17, 2022, in Cambridge, Massachusetts. (AP Photo/Mary Schwalm)

OLYMPIC GREAT KATIE LEDECKY SWIMS AROUND LIA THOMAS, NCAA LAWSUIT QUESTION

"We remain committed to working collaboratively with all stakeholders to uphold the principles of inclusivity in aquatic sports and remain confident that our gender inclusion policy represents a fair approach."

Thomas didn’t immediately respond to a request for comment from Fox News Digital.

Former NCAA swimmer Riley Gaines, who hosts the "Gaines for Girls" podcast on OutKick, and the director of Riley Gaines Center at the Leadership Institute, released a statement on the ruling.

"This ruling is a small victory for girls and women everywhere. I think we will see more wins like this both in the judicial courts and the courts public opinion as time goes on. Although he would never qualify, Thomas can still try out for the men's U.S. Olympic team. I hope the NCAA now takes a similar decisive action by stripping Thomas off all awards, titles, and records he stole from deserving female athletes."

Tyr LLP, which represented Thomas in the case, didn’t immediately respond to Fox News Digital’s request for comment.

The ruling also squashes any hope Thomas had of making the Olympics.

World Aquatics’ policy for transgender athletes essentially bans any biological male athletes from competing in women’s events unless they transitioned by the age of 12 or before undergoing "any part of male puberty."

Lia Thomas after winning a swimming meet

Lia Thomas after swimming the 100 freestyle prelims at the NCAA Swimming and Diving Championships on March 19, 2022, in Atlanta. (Rich von Biberstein/Icon Sportswire via Getty Images)

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The policy change was spurred by the International Olympic Committee’s guidelines and recommendation in November 2021 that all international federations develop their own sport-specific eligibility criteria for the women’s competition category.

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