The South African government has called on the world to fight what it calls a "gross violation of human rights law" against the country's female Olympic champion Caster Semenya.
The government says Semenya has been targeted by the International Association of Athletics Federations, which is proposing new rules to restrict the levels of testosterone in female runners.
The double Olympic champion at 800 meters is challenging the IAAF's proposed regulations at the Court of Arbitration for Sport next week.
The landmark case begins in Switzerland on Monday, with pressure from South Africa mounting on the governing body for world athletics.
"This is a gross violation of internationally accepted standards of human rights law," South Africa's sports minister Thokozile Xasa said. "Our history as a nation was in the main based on the defence of our people against human rights violations, a right to belong, that all humans are created equal.
"Therefore as the South African government we have a direct interest in the proceedings and outcome of this case. The world once declared Apartheid as a crime against human rights, and we once more call the people of the world to stand with us as we fight what we believe is a gross violation of human rights."
The IAAF's proposed rules would affect female athletes with naturally high testosterone levels running in middle distance track events between 400 meters and a mile. The athletes would be required to take medication to lower their testosterone levels and would be unable to compete for at least six months under the proposals if they wanted to carry on racing against other women.
The IAAF argues high levels of testosterone provide a performance advantage for such athletes over other women and is therefore aiming to "preserve fair competition" through the new rules.
But the South African government said the rules meant the well-being and identities of female athletes were being unfairly questioned.
"What's at stake here is far more than the right to participate in a sport. Women's bodies, their well-being, their ability to earn a livelihood, their very identity, their privacy and sense of safety and belonging in the world are being questioned," Xasa said. "These regulations have the potential to deprive the world from seeing and experiencing the natural superiority of future athletes to come from our African soils. Ms. Semenya put it so well when she said and I quote: 'It's not about me anymore. It's about the African girls who come from the rural areas who do not believe that they can do this.'
"... We therefore encourage every individual, organization and sector intolerant of discrimination, violation of human rights, particularly of women, and injustice to join and add their voice to this movement that condemn these discriminatory IAAF Regulations which in their nature seek to unfairly exclude other sections of society from competing in sport.
"We have no doubt that in no time Caster will be rising our flag in glory as she do what she does best, collecting medals."
Athletics South Africa reaffirmed its support for Semenya, who has previously undergone gender testing, the results of which have never been made public.
"ASA reaffirms its unqualified support for Caster Semenya and athletes who may be affected by the IAAF Regulations -- ASA has a duty to do so," a statement from the organisation read. "ASA wishes to express its gratitude to the South African government for supporting the legal challenge against these regulations.
"As South Africans, we all have a constitutional obligation to contest any infringements of human rights, shaped by our experiences under Apartheid."