The governing body of track argued in court that Olympic champion Caster Semenya is "biologically male" and that is the reason she should reduce her natural testosterone to be allowed to compete in female competitions, according to documents released publicly for the first time on Tuesday and which provide new insight into a bitter legal battle.
The documents released by sport's highest court show that Semenya responded by telling the judges that being described as biologically male "hurts more than I can put in words." The 28-year-old South African runner said she was unable to express how insulted she felt at the IAAF "telling me that I am not a woman."
The IAAF's stance on Semenya and other female athletes affected by its new testosterone regulations — and Semenya's outrage at the biological male claim — was revealed in a 163-page decision published by the Switzerland-based Court of Arbitration for Sport. It details parts of the courtroom exchanges that were held behind closed doors when Semenya challenged the IAAF over the highly contentious hormone rules in a five-day hearing in February. CAS had previously released only short excerpts of the final verdict when it was announced last month.
Tuesday's fuller court records, which were still redacted, show the IAAF referred to the two-time Olympic and three-time world champion as one of a number of "biologically male athletes with female gender identities."
Arguing that Semenya and others like her should be subject to its hormone limits to ensure fairness in female competitions, the IAAF stated: "There are some contexts where biology has to trump identity."
Semenya vs. the IAAF is one of the most difficult issues sport has faced.
Semenya was legally identified as female at birth and has identified as female her whole life. But the IAAF says she is one of a number of female runners in elite athletics who have medical conditions known as "differences of sex development" and who were born with the typical male XY chromosome pattern. That gives them some male biological characteristics, male levels of the hormone testosterone after puberty, and an unfair athletic advantage over other female athletes, the IAAF says.
Semenya, who has been fighting the IAAF ever since she was embroiled in a gender verification test at the world championships 10 years ago, says the rules should be discarded and she should be allowed to run in her natural form. She disputes that she has a significant performance advantage.
The IAAF won the recent case at CAS by a 2-1 majority of the panel of judges, allowing it to implement the testosterone limits.
But in the latest legal twist, Semenya appealed the CAS verdict to Switzerland's supreme court on human rights grounds. She won an interim ruling to temporarily suspend the hormone regulations and the Swiss supreme court will hear her full appeal.
The rules only apply to certain races, from 400 meters to one mile, but they include Semenya's specialist two-lap event.
To be allowed to compete under the rules, Semenya and other affected athletes must medically reduce their testosterone to below a specific threshold set by the IAAF. The IAAF gives three options to do that: A daily contraceptive pill, a monthly hormone-blocking injection, or surgery.
The medical process has been criticized as unethical by experts and Semenya has refused to take medication to alter what she calls her genetic gifts. At least two other runners, Francine Niyonsaba of Burundi and Margaret Wambui of Kenya, who are both Olympic medalists, say they are also affected by the rules. They have also railed against the regulations and criticized the IAAF.
Tuesday's CAS documents shone a light on some of the details of the battle between Semenya and the IAAF over the last decade, much of which Semenya hadn't publicly spoken about despite her story making headline news across the world.
Semenya said in witness statements to the CAS that she had been subjected to gender verification tests that included an intrusive physical examination ordered by South African track authorities in the buildup to the 2009 world championships without being told or understanding the nature of the tests. She was 18 at the time.
Then, after her breakthrough victory at those championships in Berlin, Germany, Semenya said she was taken to a hospital where the IAAF conducted another test on her. Semenya said the IAAF did not ask her if she wanted to undergo the test.
"It was an order by the IAAF which I had no choice but to comply with," Semenya said.
She described the world championships and the public speculation that erupted over her gender as "the most profound and humiliating experience of my life."
Semenya also described a five-year period from 2010-15 where she reluctantly agreed to take testosterone-suppressing oral contraceptives recommended by the IAAF so she could continue running.
They caused significant weight gain, made her constantly feel sick, led to regular fevers and internal abdominal pain, she said.
She said the IAAF had used her as a "lab rat" as it experimented with a medical process it would later introduce as part of its testosterone rules.
In a statement released later Tuesday, Semenya said: "I will not allow the IAAF to use me and my body again."