A male swimmer is now identifying as female and is unsurprisingly smashing female records.

Lia Thomas, a biological male who identifies as female, swam for Penn's men's swimming team for three years in NCAA Division I competition.

Thomas took a year off from competition to transition and returned as a commanding force in the water.

Since joining Penn's women's swimming and diving roster, Thomas has achieved more top placements than in prior years.

At a tri-meet for the University of Pennsylvania, Cornell University, and Princeton University on Nov. 20, "Thomas blasted the number one 200 free time and the second-fastest 500 free time in the nation ... breaking Penn program records in both events," according to a collegiate swimming report .

Thomas won the 100 free, 200 free, and 500 free, sweeping the events, and also helped Penn win the 400 free relay.

Despite winning by significant margins the male swimmer claims his “transition has had no effect on performance”.

“The process of coming out as being trans and continuing to swim was a lot of uncertainty and unknown around an area that's usually really solid,” Thomas said.

“Being trans has not affected my ability to do this sport, and being able to continue is very rewarding.”

Binary spokeswoman, Kirralie Smith, said of course he would still be able to swim and beat women.

“Thomas has retained all the advantages of being male,” she said.

“Taking a few pills or putting on a costume does not negate the fact he enjoyed the benefits of testosterone during his development.

“It is insulting and unfair that he is permitted to compete in the female category, as he is 100 per cent male.”