She has failed to meet the conditions for eligibility established by World Athletics.
Transgender runner CeCe Telfer will not be allowed to compete in the women's 400m hurdles at the US Olympic trials.
Telfer had competed for the men's team at Franklin Pierce University in New Hampshire, but took time off, before returning to compete for the women's team. In 2019, Telfer win the NCAA title.
Telfer had been entered in the trials that are taking place this week. However, in 2019 World Athletics put out new guidelines that barred athletes whose testosterone levels were at 5 nanomoles per litre (nmol/L) or more from competing at women's events of between 400 meters and a mile.
NECN reports that, despite being on the list of qualified athletes for Friday's heats, Telfer was not included on a start list for the heats that was published on Wednesday evening. USA Track and Field (USATF) released a short statement saying that athletes must meet the World Athletic requirements to be eligible for trials.
The organisation said that it had been notified last week that Telfer had not met the conditions.
Telfer's manager, David McFarland, said in a statement that they would respect the decision.
He said: "CeCe has turned her focus towards the future and is continuing to train. She will compete on the national — and world — stage again soon."
To be eligible for women's events at a distance between 400 metres and a mile, athletes must stay below the 5 nmol/L threshold for 12 months before an event. The World Athletics guidelines say that athletes can lower their testosterone levels using an oral contraception pill, a monthly injection of a hormone therapy drug or by surgery to remove their testicles.
"It is their choice whether or not to have any treatment, and (if so) which treatment to have," World Athletics said in a Q&A discussing its policy.
However athletes such as Caster Semenya refuse to do so, arguing that doing so could endanger her health, and that rules such as this deny her and other athletes with differences of sexual development (DSD) the right to rely on their natural abilities.
In a statement, USATF said it "strongly supports inclusivity and providing a clear path to participation in the sport for all, while also maintaining competitive fairness."
"If CeCe meets the conditions for transgender athlete participation in the future, we wholeheartedly back her participation in international events as a member of Team USATF," the statement said.
Recently, New Zealand weightlifter Laurel Hubbard
became the first transgender athlete ever to be selected to compete at an Olympics.
