(NewsNation) — A swimmer at the University of Pennsylvania said the situation surrounding transgender swimmer Lia Thomas is “insane.”

Thomas formerly competed as a member of Penn’s men’s swimming team for three years, identifying as a male. Now, she is shattering records on the women’s team as one of the top swimmers in the nation since starting her transition.

Some of her teammates say her success in the pool isn’t fair. They have not shared their stories publicly — until now. 

One of Thomas’ teammates sat down for an exclusive interview with NewsNation investigative correspondent Rich McHugh. She wanted to talk, but feared worldwide backlash, so we’ve agreed to guarantee her anonymity.

She supports Lia’s transition, but feels like she and her teammates aren’t being heard.

“The first word that comes to my mind is insane,” the swimmer told NewsNation. “I feel like it’s something that’s so basic that people have just somehow managed to twist and make [it] way more complicated than it should have ever been.”

Transgender competition in sports has become a lightning rod political issue. Several Republican-led states have passed laws banning grade school students from competing against athletes of the opposite biological sex. The Department of Justice has called those laws unconstitutional.

Things are more complicated at the NCAA level. They do not have a universal policy on trans athletes. Instead, they follow the national governing body’s guidelines for each sport. USA Swimming allows Thomas to compete based on her testosterone levels.

The Penn swimmer we spoke with was critical of the rules.

“I think we’re going to look at the people who are making these decisions and were in charge and kind of laugh at them,” she said. “And then just ask, ‘What were you doing? You had the power to change that and you chose not to. You’re kind of a coward for that.’”

To hear her reaction to Thomas’ record-breaking year, and why she says she feels silenced by her coaches, the university and the NCAA, watch Tuesday night on NewsNation Prime at 8p/7c.