More than 3,000 people were at OR Tambo International Airport in Johannesburg yesterday to welcome home athlete Caster Semenya, the new 800m world champion.

The 18-year-old has been at the centre of an acrimonious row with international athletics officials over her gender.

At an athletics meet in Berlin last week Ms Semenya won the 800m in 1min 55.45sec but questions were raised as to whether she is indeed a woman.

The President of Athletics South Africa, Leonard Chuene, has stepped down from the International Association of Athletics Federations (IAAF) council while it investigates her, while in her homeland there are accusations she is the victim of racism and sexism.

“We have not once, as the ASA, doubted her,” he said.

“It’s very simple; she is a girl.”

A group of doctors including an endocrinologist, a gynaecologist, an internal medicine expert, as well as gender experts will begin a testing procedure, but it could be months before the full results are known.

The IAAF admit that if the athlete was always told she was a woman but is not then she would not necessarily have cheated.

South Africa’s President has expressed his support for Ms Semenya.

“She has shown the world that if you are determined to win, nobody and nothing will stop you,” said Jacob Zuma.