The 28-year-old, who is also a three-time world champion, launched a legal case after the IAAF announced a new rule which, if upheld by CAS, would force her to take medication to reduce her testosterone levels or compete against men.

The IAAF has long argued that female athletes like Semenya, who have unusually high levels of testosterone caused by differences of sexual development (DSD) have an unfair advantage over women with normal testosterone levels.

They have received widespread criticism for their stance and a case on the issue began at the CAS in Lausanne yesterday.

As proceedings began the IAAF released the names of expert witnesses it plans to call at the case, which sparked uproar among Semenya’s legal team, who claimed the disclosure breached the court’s confidentiality rules.

“Ms Semenya believes the IAAF press release is a clear breach of the confidentiality provisions that was orchestrated in an effort to influence public opinion in circumstances where the IAAF knew that Ms Semenya would not be prepared to respond because she was complying with her confidentiality obligations,” they said.

The experts the IAAF named included Angelica Linden Hirschberg, a professor of obstetrics and gynecology in Stockholm, David Handelsman, a professor of reproductive endocrinology and andrology in Sydney and Doriane Lambelet Coleman, who is a professor of law at Duke Law School in the United States and is also a former two-time Swiss national champion over 800m.

In response Semenya’s lawyers said the CAS had granted permission for her to release a list of her own “as a matter of fairness” and she has now done so.

It lists seven individuals including another professor of obstetrics and gynecology Veronica Gomez-Lobo, who works at Georgetown University in the United States.

Also named is the director of the Sports Genomics Laboratory at Manchester Metropolitan University Alun Williams, who Semenya’s team say has published “numerous academic papers on the topic” and Roger Pielke Jr, the director of the Sports Governance Centre at the University of Colorado.

“She is grateful to the CAS for opportunity to present her case and for granting her permission to disclose her list of experts publicly in response to the IAAF,” Semenya’s lawyers said yesterday.

“Going forward, the CAS has reiterated that the arbitration proceedings are confidential and information about the case should not be disclosed publicly.”

The other names on Semenya’s list are Eric Vilain, a geneticist specialising in gender based and endocrine genetics including DSD, Dankmar Bohning, Richard Holt and Anthony C Hackney.

Bohning is a professor of medical statistics at the University of Southampton, Holt is a professor of diabetes and endocrinology, also at the University of Southampton and Hackney is a professor at the University of North Carolina in the US, who holds a PhD in exercise physiology.

The case is due to be heard by the CAS for at least five days, with a verdict expected in March.

Since Semenya announced her legal challenge last year various bodies have announced their public support, including three human rights experts at the United Nations who called the IAAF’s stance “unjustifiable”, the group Human Rights Watch, the Women’s Sport Foundation and the South African Government.

The IAAF however has remained insistent that the rule is necessary in the interest of fairness.

"The core value for the IAAF is the empowerment of girls and women through athletics," IAAF President Sebastian Coe said, as he arrived at the CAS in Lausanne.

"The regulations that we are introducing are there to protect the sanctity of fair and open competition."

If the rule is upheld it will come into force on March 26 and will see Semenya unable to compete for much of the 2019 outdoor season.

This is because the rule dictates athletes with her condition must take medication to reduce their testosterone levels for at least six months before competing.