The use of genetics in sports to test the gender of athletes must be revisited in the wake of the controversial case of South African champion runner Caster Semenya, an expert said on Wednesday.

"In the Caster case, everything went wrong from the beginning," University of Cape Town academic Ambroise Wonkam said at a conference of African societies of human genetics.

Semenya landed in the global spotlight after tests into her gender were made public by the International Association of Athletics Federations (IAAF) shortly before the athlete won gold in Berlin 2009, after also undergoing tests at home.

The gold medalist's case had highlighted the shortcomings in the sex verification tests used in sports, with complex results that sometimes present genetic findings that differ from clinical exams.

"The number of genetic abnormalities and their complexity... make this policy of gender testing, at least using genetics, inadequate and the revision is totally long overdue if not stopped," Wonkam said.

The highly politicised issue caused public anger in South Africa after leaked test results said Semenya was a hermaphrodite. However she was cleared to compete as a woman by the IAAF in July last year after nearly a year of speculation.

"It's not just a medical or scientific issue," said Wonkam. "It's also a legal, a social, a psychological and a functional issue that is not totally solved in some cases. Becaues of the variables, because we don't know how to interpret them."