University of Pennsylvania star Lia Thomas swept aside her competition again as the transitioned 22-year-old won a 100-yard race by almost a second and a 200-yard race by a wider margin in a meet against Harvard University.
Former men's team competitor Thomas, who went through puberty and has had hormone-suppression therapy, picked up more honors in the same week a female teammate accused her of plotting to lose amid increasing disquiet about her dominance in the pool.
Thomas broke school and national records at the start of 2022 and has triumphed again just days after governing body USA Swimming pledged to publish new guidelines around elite transgender athletes.
Critics of Thomas's involvement say the current rules threaten the fairness of female sports and should be revised, while their opponents have endorsed the rights of transgender swimmers to compete in the gender category they identify with as long as they have carried out the required period of hormone treatment.
The National Collegiate Athletic Association (NCAA) has approved new guidelines which will allow the national bodies of each sport to determine its policy for transgender participation.
An NCAA committee will then scrutinize those terms and make recommendations.
Transgender student-athletes must document their testosterone levels to prove that they meet sport-specific requirements four weeks before any championship call-ups.
Colleen Young, who won bronze at the 2015 World Championships and 2016 Paralympic Games, used social media to voice her misgivings.
"Lia Thomas is a biological male swimming against biological females," said the former Pan-American record-setter.
"Whether she identifies as a girl is irrelevant to the fact that she was born a male, went through puberty as a male and swam on the men's team for three years. Protect women’s sports."
Former gold medal-winning decathlete Caitlyn Jenner and swimming icon Michael Phelps spoke out earlier this week against Thomas participating against rivals born as women.
Jenner admitted she is baffled by the situation, calling it "unfortunate" and warning that "this woke world that we are living in right now is not working."