Three global organisations that promote women's sport have written to athletics' governing body the IAAF to say its rules for intersex athletes are "discriminatory" and "enforce gender inequality".
The IAAF has come under strong criticism from academics, campaigners and doctors ever since double Olympic 800 metres champion Caster Semenya failed in her bid to stop the introduction of a new testosterone limit for female athletes who want to compete internationally between 400 metres and a mile.
On Wednesday, Semenya confirmed that she has filed an appeal against the Court of Arbitration for Sport ruling at the Federal Supreme Court of Switzerland but, in the meantime, the testosterone limit is in place.
The IAAF's determination to implement its rule in the face of so much opposition has now prompted the International Working Group on Women and Sport, WomenSport International and the International Association of Physical Education for Girls and Women to express their "great disappointment", too.
In a joint statement, they said they were "particularly disappointed" that the IAAF decided to enforce the limit immediately after the CAS verdict earlier this month, which means affected athletes must take testosterone suppressants and submit to regular checks.
"It is (our) collective view that this is discriminatory and in no way do we support a ruling that forces an athlete to take medication that alters their natural state," they said.
"We believe that affected athletes are being penalised for their biological traits, over which they have no control, and that such penalty enforces gender inequality, because it does not apply to male athletes.
"We believe this infringes their human rights. The affected athletes have not cheated or been found to be taking performance-enhancing drugs, yet this decision implies wrong-doing and comes with a penalty."
They continue by saying the IAAF policy contravenes the principles the Monaco-based federation signed up to when it became a member organisation of the International Working Group on Women and Sport.
And they add that while they recognise the inclusion of athletes with high testosterone in women's sport is a "complex issue that continues to challenge many organisations", no single sporting federation has the right to impose such restrictions and they should wait for more research and the development of a global consensus on the matter.
Their letter concludes by saying they support Semenya's attempt to have the rule overturned on appeal.
The 28-year-old South African won her 30th consecutive race over 800m at the Diamond League meeting in Doha on May 3, two days after the CAS verdict was announced. Her next scheduled race is over 3,000 metres – currently not one of the IAAF's restricted events – at the Prefontaine Classic in Oregon on June 30.
