A showdown is looming in Lausanne, Switzerland, between one of the fastest women in the world and the organization that says she has to take a testosterone suppressant to compete.

Lawyers for Olympic champion Caster Semenya say she is “unquestionably a woman” and has every right to race internationally without “unnecessary medical intervention.”

On Monday, the international Court of Arbitration for Sport is to hear the claim of the South African 800-meter runner against the IAAF over what she says are discriminatory rules.

In response, the IAAF told the British newspaper The Guardian it “accepted their legal sex without question” and was not classifying any athletes with differences in sexual development, known as DSD, as male. Athletes with DSD who identify as female can continue to compete as women.

The organization wants the CAS to rule that athletes like Semenya, who was reportedly born with internalized testicles, must have their testosterone reduced to female levels before they compete internationally in order to ensure fairness with other women.

But to Semenya, what’s fair is that she be “celebrated, not discriminated against.”

“Her case is about the rights of women such as Ms. Semenya who are born as women, reared and socialized as women, who have been legally recognized as women for their entire lives, who have always competed as women, and who should be permitted to compete in the female category without discrimination,” said her attorneys in their statement.

The IAAF maintains: “If a DSD athlete has testes and male levels of testosterone, they get the same increases in bone and muscle size and strength and increases in haemoglobin that a male gets when they go through puberty, which is what gives men such a performance advantage over women.

“Therefore, to preserve fair competition in the female category, it is necessary to require DSD athletes to reduce their testosterone down to female levels before they compete at international level.”

Their published rules state:

“…any athlete who has a Difference of Sexual Development (DSD) that means her levels of circulating testosterone (in serum) are five (5) nmol/L or above and who is androgen-sensitive to meet the following criteria to be eligible to compete…”

  • (a) she must be recognized at law either as female or as intersex (or equivalent);
  • (b) she must reduce her blood testosterone level to below five (5) nmol/L for a continuous period of at least six months (e.g., by use of hormonal contraceptives); and
  • (c) thereafter she must maintain her blood testosterone level below five (5) nmol/L continuously (ie: whether she is in competition or out of competition) for so long as she wishes to remain eligible.

But Katrina Karkazis, a leading expert in testosterone and a senior research fellow with the Global Health Justice Partnership at Yale University calls bullshit on the IAAF’s stance.

She told the BBC the IAAF was “blithely and opportunistically misrepresenting the science of sex biology” and seeking “to create its own definition of sex based on erroneous beliefs about biology and gender”.

“It is unfounded and cruel and will do even more harm by fostering misunderstanding and further discrimination,” said Karkazis.

Journalist Oliver Brown wrote in The Telegraph that in 2009, he visited Semenya’s hometown, the village of Ga-Masehlong in South Africa, and spoke to her mother, Dorcus about her daughter’s critics.

‘‘They are just jealous,’’ she told Brown. ‘‘They don’t want to see black people improving themselves – they can go to hell.” Referring to her daughter by her first name, she added:

“Mokgadi is a girl.’’