South Africa plans to lodge a complaint with the UN High Commissioner for Human Rights over the gender test ordered on the country's middle-distance runner Caster Semenya, officials said Friday.

The Portfolio Committee on Sport and Recreation soon said the commissioner needed to investigate the "gross and severe undermining of rights and privacy" by the ruling athletics body IAAF.

Semenya's gender has been under scrutiny since her arrival in Berlin for the World Athletics Championship where she won a gold medal in the women's 800 metres race.

The IAAF has asked Semenya to undergo a gender verification test as there were doubts about her gender, given her muscular physique.

"The humiliation of Semenya was a sign of sexist action by IAAF as it undermined the achievements of women," sports committee chairman Butana Komphela said in a statement.

The IAAF said on Friday it had to conduct the test to make sure she doesn't have an unfair advantage over her opponents after a sudden burst onto the scene.

In a statement, the IAAF said it regretted allegations being made against the athlete and that the tests are "still underway to verify the gender of Caster Semenya further to remarkable improvements in the athlete's performance in recent months.

"These tests do not suggest any suspicion of deliberate misconduct but seek to assess the possibility of a potential medical condition which would give Semenya an unfair advantage over her competitors.

"The IAAF recognises the sensitivity of this issue and deeply regrets the allegations being made about the reasons for which these tests are being conducted," the IAAF said in Berlin.

The statement comes in the wake of a storm of outrage in South Africa which has rallied behind the 18-year-old who came almost out of nowhere to take the gold on Wednesday in the Olympic Stadium with a huge margin, running eight seconds faster than her best 2008 time.

Some four hours before the final the IAAF confirmed it had asked Semenya to undergo the gender verification test. The athlete has since been shielded from the media, but it emerged on Friday in South Africa that Semenya had considered rejecting the gold medal over the affair.

Citing South African athletics chief Leonard Chuene, The Times daily said that Semenya had to be convinced by Chuene to attend the medal ceremony on Thursday night in Berlin and to accept the medal.

"She said she did not want to go on the podium, but I told her she must," said Chuene.

Chuene presented Semenya with the gold medal at the ceremony during which the 18-year-old runner received a big cheer from the Berlin crowd.