The two-time Olympic 800 metres champion challenged a new IAAF ruling that will require her to take medication to lower her testosterone levels in order to compete against women in track events ranging from 400m to a mile.
Semenya ruled out retiring after winning the 800m at the Diamond League event in Doha, just two days after the CAS ruling was announced at the start of this month.
The new regulation has since been implemented and Semenya has now launched a fresh appeal amid uncertainty over her future in the sport.
