South African athlete Caster Semenya says she has a target on her back because she is the best at what she does. Speaking on the sidelines of a Top Women Conference in Johannesburg, she says people don't question differences in men who compete against each other, but they do in women. Semenya is banned from defending her world 800m title in Doha in September by a Swiss court ruling which revoked a temporary suspension on the IAAF's controversial testosterone-curbing rules.

Caster Semenya will not compete at the World Championships after a Swiss judge over-turned a temporary suspension on controversial testosterone rules. The South African is the current 800 meter world champion.

Olympic 800 metres champion Caster Semenya has accused the global athletics governing body of using her as a human guinea pig as it emerged that the IAAF had sought to have her declared a "biological male" in proceedings before sport's highest court.

Olympic 800 metres champion Caster Semenya filed an appeal to Switzerland's highest court on Wednesday against rules requiring middle-distance female athletes with a high natural level of testosterone to reduce it via medication.

South Africa's government has said it wants an appeal to be lodged against rules that force some female athletes to reduce testosterone levels. Olympic champion Caster Semenya had challenged the new regulations.

"I switch race when I want to switch races, so no man can tell me what to do", reacts Caster Semenya after winning Doha 800m in first race since gender ruling defeat.

Champion sprinter Caster Semenya has lost her appeal against regulations limiting testosterone levels in certain women's athletic events. The judges found the rule "discriminatory" but also said limits were necessary.