Semenya offered to show her body to officials to prove she was female

South Africa's Caster Semenya waits for the start of the 800-meter semifinal race during the athletics competitions of the 2016 Summer Olympics at the Olympic stadium in Rio de Janeiro, Brazil. AP

Double Olympic 800 metres champion Caster Semenya offered to show her vagina to athletics officials when she was 18 to prove she was female, the South African middle-distance runner said in an interview with HBO's Real Sports that will air on Tuesday.

Semenya, now 31, burst onto the scene in 2009 when she won the women's 800m world title by a stunning margin hours after the sport's world governing body said she would undergo gender verification tests.