CASTER SEMENYA has asked the Court of Arbitration for Sport to rule the International Association of Athletics Federations’ testosterone regulations “unlawful.”

CAS yesterday issued a statement saying it had been asked to rule on the IAAF regulation compelling some female athletes to medically lower naturally occurring testosterone, which comes into effect on November 1.

The South African, a two-time Olympic and three-time world 800 metres champion, has hyperandrogenism, a medical condition characterised by excessive levels of male sex hormones such as testosterone.