Johannesburg - World champion athlete Caster Semenya has arrived home in South Africa to reports she has recorded "elevated levels of the male hormone testosterone" in testing.

GALLERY: Caster Semenya arrives in SA

GALLERY: Caster Semenya wins 800m gold

VIDEO: Caster Semenya wins 800m gold

VIDEO: Caster Semenya interviewed

Preliminary medical tests taken on the 800 metres gold medallist before the start of the World Championships indicated she had three times the normal female level of testosterone, according to the UK's Telegraph newspaper.

The paper claims the information has prompted the International Association of Athletics Federations (IAAF) to ask the South African athletics body to carry out a detailed "gender verification" test on Semenya.

Meanwhile, it has emerged that the head coach of the South African national team, Dr Ekkart Arbeit, has a controversial history.

Arbeit was accused by East German shot-putter Heidi Krieger of giving her so many anabolic steroids she was forced to undergo a sex-change operation.

It is unclear how closely Arbeit worked with Semenya, but he has insisted that since the fall of the Berlin Wall in 1989, he has had no involvement with performance-enhancing drugs and that his training methods are clean.

The ANC Youth League has accused the IAAF of racism.

"We must celebrate our athlete's victory despite the attempts by racist institutions to undermine what she has achieved. We are proud of her," ANCYL's national spokesperson Floyd Shivambu told the BBC.

South Africans have also rallied behind her, with family members showing the BBC a birth certificate.

Medical tests on the athlete are said to be ongoing, with the results not expected for several weeks.

IAAF president Lamine Diack said he regretted the public row over the athlete and admitted the affair could have been treated more sensitively.

"It should not even have become an issue if the confidentiality had been respected. There was a leak of confidentiality at some point and this led to some insensitive reactions," he said.