Article published on the 2009-08-20 Latest update 2009-08-20 11:13 TU
The International Association of Athletics Federations said it had requested the test three weeks ago.
A group of doctors, including an endocrinologist, a gynaecologist, an internal medicine expert, an expert on gender and a psychologist, have started the testing procedure. Results are not likely to be known for some time.
"The gender verification test is an extremely complex procedure,” said the IAAF’s Nick Davies.
“Today, we do not have any conclusive evidence that she should not be allowed to run."
Semenya won gold in impressive fashion on Wednesday, hitting the tap in a time of one minute, 55.45 seconds. Defending champion Janeth Jepkosgei trailed in 2.45 seconds further back to take silver.
But questions have been asked about whether Semenya, who avoided the post-race press conference, is a female or a male.
Suspicions were raised by the speed with which she has emerged on the women’s scene – she only hit the world stage last month when she ran 1.56.72 in Bambous, smashing her previous personal best by more than seven seconds - and what some commentators are calling her “boyish” appearance.
South Africa’s Olympic governing body and Semenya’s family have both expressed anger at the decision to test her.
"We condemn the way she was linked with such media speculation and allegation, especially on a day she ran in the final of her first major world event," said Gideon Sam, president of South Africa's Olympic governing body, SASCOC.
The athlete’s father Jacob Semenya spoke out in the tabloid Sowetan which dubbed the champion "Our Golden Girl".
"She is my little girl. I raised her and I have never doubted her gender. She is a woman and I can repeat that a million times," he said.
"For the first time South Africans have someone to be proud of and detractors are already shouting wolf. It is unfair. I wish they would leave my daughter alone."
Semenya’s 80-year-old grandmother Maphuthi Sekgala has also weighed into the argument.
"[The controversy] doesn't bother me that much because I know she's a woman -- I raised her myself," she told South African newspaper, The Times.
"She called me after (the heats) and told me that they think she's a man. What can I do when they call her a man, when she's really not a man? It is God who made her look that way."