Transgender swimmer Lia Thomas will not compete at Olympics after legal battle dismissed

World Aquatics has hailed the decision

The 25-year-old had launched legal action against the governing body over their decision to ban transgender women from competing in women's elite races if they have gone through any part of the process of male puberty.

World Aquatics (WA) had voted on the ban in 2022, but Thomas, who became the first transgender athlete to win the highest US national college title in March 2022, argued the rules were discriminatory.

The swimmer was attempting to overturn the ban at the Court of Arbitration for Sport (Cas).

However, the case has been dismissed by Cas after they determined Thomas was not eligible to challenge WA's rules, the BBC reports.

Their 24-page verdict said Thomas was "simply not entitled to engage with eligibility to compete in WA competitions" as someone who was no longer a member of USA swimming.

This means Thomas will not be allowed to compete at the Paris Olympics next month.

WA has hailed the ruling as a "major step forward in our efforts to protect women's sport".

The body said in a statement: "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.

"Our policies and practices are continuously evaluated to ensure they align with these core values, which led to the introduction of our open category.

"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 has labelled the decision "deeply disappointing", adding: "Blanket bans preventing trans women from competing are discriminatory and deprive us of valuable athletic opportunities that are central to our identities.”

WATCH: Asking Parklife how they're going to vote at the general election