South African middle distance runner Caster Semenya has withdrawn from the women's 4km race at the South African Cross Country Championships in Pretoria on Saturday.

Semenya has not competed since winning the world 800m title in Berlin last month in the midst of an ongoing controversy surrounding her gender.

Australian media claimed on Friday that the IAAF had received results of gender verification tests that prove Semenya is partly genetically male and that the 18-year-old faces a possible ban from competing against women.

On Friday morning Athletics South Africa cancelled a press conference scheduled with Semenya in Pretoria on Saturday, and later in the afternoon her coach, Michael Seme, confirmed she would not take part in her last race of the season.

"We have decided that Caster will not run tomorrow," Seme said.

When pushed for a reason, he added that she was "not feeling well."