(CNN) Three Connecticut high school athletes are challenging the state's policy of letting transgender athletes compete on sport teams based on their gender identity.

The students filed a federal complaint with the US Department of Education claiming the policy violates Title IX , the federal law that aims to ensure students have equal access to opportunities regardless of their sex.

The complaint was filed Monday on behalf of three female track athletes by Alliance Defending Freedom (ADF), a faith-based non-profit legal organization. Only one of the athletes, Selina Soule, was named. The complaint said the other two withheld their names for fear of retaliation.

The complaint says transgender athletes should be banned from competing in the category corresponding with their gender identity, claiming that allowing them to do so results in "boys displacing girls in competitive track events."

Allowing transgender girls, whom the complaint refers to as "biological males," to compete with other girls violates the mandate of Title IX for equal athletic opportunities, according to the ADF.

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