CAPE TOWN - Double Olympic champion Caster Semenya will not defend her 800-metres title at the World Championships in Doha in September.

This after the Swiss Federal Tribunal reversed a ruling that temporarily lifted the IAAF’s testosterone regulations imposed on her, a spokesman for the athlete said on Tuesday.

Semenya is appealing the Court of Arbitration for Sport (CAS) ruling on 1 May that supported the IAAF’s regulations.

The regulations say XY chromosome athletes with differences in sexual development (DSDs) can race in distances from 400m to a mile only if they take medication to reach a reduced testosterone level.