An appeal hearing is underway at the Swiss-based Court of Arbitration for Sport (CAS) in a landmark case with wide-reaching consequences for gender politics and science.
The international three-judge panelexternal link in the city of Lausanne is considering an appeal by Caster Semenaya, a South African 800-metres double Olympic champion, against a new set of regulations by the International Association of Athletics Federationexternal link (IAAF) aimed at lowering the testosterone levels of hyperandrogenic athletes.
The scheduled five-day appeal case is among the longest ever heard by the sports court and a verdict is expected by the end of March.
The IAAF wants to require women with naturally elevated testosterone to lower their levels by medication before being allowed to compete in world-class races from 400 metres to one mile.
The planned rule has prompted accusations of sexism and racism.
Previous attempts to regulate testosterone in female athletes fell foul of a CAS ruling in 2015 following an appeal by Indian sprinter Dutee Chand.
Decisions of the CAS can be appealed to Switzerland’s Supreme Court.
swissinfo.ch with Reuters and AP/urs