The IAAF will challenge the court's order ©Getty Images

The International Association of Athletics Federations (IAAF) will seek a "swift reversion" to a decision from the Federal Supreme Court of Switzerland which allows Caster Semenya to compete without taking medication to lower her testosterone while her appeal is pending.

The Supreme Court on Monday (June 3) ordered the rules which force athletes with differences in sexual development (DSD) to take drugs to medically reduce their naturally-occurring testosterone if they want to compete at events ranging from 400 metres to a mile be put on hold with immediate effect.

The court said its "superprovisional order", considered a major boost for Semenya in her challenge against a Court of Arbitration for Sport decision which ruled in the IAAF's favour, would be in place until June 25.

In response, the IAAF said it would "seek a swift reversion of the superprovisional order moving forwards so that the DSD Regulations apply to all affected athletes in order (among other things) to avoid serious confusion among athletes and event organisers and to protect the integrity of the sport".

The worldwide governing body also confirmed the court's ruling only applied to the South African double Olympic and three-times world champion over 800m.

The IAAF said it had only been informed of the Supreme Court's decision yesterday afternoon, almost 24 hours after it was made public by Semenya's legal team.

The Supreme Court ordered the regulations be immediately put on hold following the CAS decision ©Getty Images
The Supreme Court ordered the regulations be immediately put on hold following the CAS decision ©Getty Images

This meant the IAAF had not been able to "explain why the DSD Regulations should remain in force and applicable to all affected athletes while the appeal is pending". the body claimed.

"The IAAF fully respects each individual's personal dignity and supports the social movement to have people accepted in society based on their chosen legal sex and/or gender identity," the statement added.

"However, the IAAF is convinced there are some contexts, sport being one of them, where biology has to trump identity.

"The IAAF also believes the right to participate in sport does not translate to a right to self-identify into a competition category or an event, or to insist on inclusion in a preferred event, or to win in a particular event, without regard to the legitimate rules of the sport or the criteria for entry."

The rules, which came into force on May 8, mean DSD athletes with naturally high levels of testosterone who wish to participate in events between 400m and a mile must medically limit that level to under 5 nmol/L, double the normal female range of below 2 nmol/L.

They were described as "discriminatory" by the CAS when it ruled in favour of the IAAF and against Semenya but also said the policy was "necessary, reasonable and proportionate" to protect the fairness of women's sport.