Looking shy and awkward under the glare of media attention, South African runner Caster Semenya returned home Tuesday amid questions about her gender after her stunning 800-meter win at the world championships.

The president of Athletics South Africa, Leonard Chuene, was defiant and said he had resigned from his seat on the IAAF board to protest the organization's treatment of Semenya. She is not accused of trying to cheat, but of perhaps unknowingly having a medical condition that blurs her gender and gives her an unfair advantage.

"We are not going to allow Europeans to describe and define our children," he told a news conference, which Semenya attended although she did not address reporters.

Semenya's victory in Berlin came after world athletics officials said they were conducting gender tests after questions arose about her muscular build and deep voice. South Africans have embraced her achievement despite the questions.

Semenya was greeted warmly at the airport in Johannesburg by several thousand singing and dancing fans. A homemade poster held by a fan at the airport declared Semenya "our first lady of sport."

The 18-year-old, dressed in her team tracksuit with her gold medal around her neck, then was brought to a stage set up in the parking lot.

"Hi everybody," Semenya told the roaring crowd of fans. Standing in a row with the other South African medalists, she gave a thumbs-up sign and waved to people in the crowd. The smiling teenager also joined in with the dancing for a short while before being embraced by her younger siblings.

Semenya also was welcomed home by her parents and Winnie Madikizela-Mandela, the former wife of the country's first black president Nelson Mandela.

"We are here to tell the whole world how proud we are of our little girl," Madikizela-Mandela told the cheering crowd of fans. "They can write what they like — we are proud of her."

Semenya's mother Dorcus, wearing a traditional headdress, stood beaming at her daughter.

"She has lifted our hearts," she said. "We feel powerful because of her."

On Tuesday, Semenya spoke very briefly at the presidential guest house in Pretoria after South African President Jacob Zuma gave a speech celebrating the athletes' return. Semenya strode confidently to the podium and described her last race and those that led to it.

She said that before her final 800-meter race, her coach told her, "'last 200, kill them. I did what he said, but I took a lead in the last 400. I celebrated the last 200. It was great," she said with a smile as her teammates stood up to applaud.

Zuma said South Africa's minister of sport and recreation has written to the IAAF to express "our disappointment and the manner in which the body has dealt with the matter," he said.

"It is one thing to seek to ascertain whether or not an athlete has an unfair advantage over others, but it is another to publicly humiliate an honest professional and competent athlete."

When asked what he would do if the IAAF ruled to revoke the medal, he said, "they're not going to remove the gold medal. She won it. So that question does not arise."

The IAAF, track and field's governing body, will decide Semenya's case according to whether her "conditions ... accord no advantage over other females" after consulting a gynecologist, an endocrinologist, a psychologist, an internal medicine specialist and a gender expert.

Her genes and physiology as well as how she sees herself and how she is seen by her community could play a role in their determination.

Semenya's supporters say the allegations against her are motivated by jealousy and show racial discrimination against Africans.

On Sunday, Lamine Diack, the IAAF president, said the affair was handled badly.

"I deeply regret that confidentiality was breached in this case and that the IAAF were forced into a position of having to confirm that gender testing was being carried out on this young athlete," Diack told reporters in Berlin. "It is a regrettable matter and I have requested an internal inquiry to ensure that procedures are tightened up and this never happens again."