Caster Semenya’s lawyers have accused the International Association of Athletics Federations of using underhand tactics to gain public support at the start of their contentious dispute at the court of arbitration for sport in Lausanne.

The two-times Olympic 800m champion is challenging the introduction of revised eligibility rules for athletes with disorders of sexual development in a case that could have enormous implications.

With so much at stake, it is unsurprising that both sides have been sniping at each other over the last week.

On Friday, the South Africa sports minister, Thokozile Xasa, launched a social media campaign to back her compatriot and accused the IAAF of racism. World athletics’ governing body responded with a press release that restated its case and listed five of the experts it intends to call at CAS. An hour later, Semenya’s lawyers issued a statement that strongly criticised the move and questioned the IAAF’s motives.

They said: “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.” Semenya’s lawyers added they have raised this issue with Cas and, “as a matter of fairness”, they will be revealing the names of their experts supporting their case on Tuesday .

A spokesperson for the IAAF said: “The IAAF does not believe the list of witnesses it will be calling is confidential, just their evidence at Cas. Cas left the decision for all parties to release their witness list to the parties involved. This was agreed.”

The IAAF said it was acting because it wants to “empower girls and women” by maintaining a level playing field. “The female category in sport is a protected category,” it said.

“For it to serve its purposes, which include providing females opportunities equal to males, it must have eligibility standards that ensure athletes who identify as female but have testes, and testosterone levels in the male range, at least drop their testosterone levels into the female range in order to compete at the elite level in the female classification.

“This standard is necessary to ensure fair competition for all women. Indeed, without it, we risk losing the next generation of female athletes, since they will see no path to success in our sport.”

The IAAF named three leading professors of endocrinology, a sports law expert and a transgender medical physicist as being among the experts it will call on this week.

The IAAF is adamant it has evidence to support its testosterone limit and is intending to introduce the rule on 26 March, six months later than planned to allow for Semenya’s challenge. If the rule survives Semenya’s challenge, athletes wishing to compete in the relevant events will need to reduce their testosterone levels to five nanomoles per litre (nmol/L) for at least six months before racing.

Cas has promised to make a ruling on the matter within a month. PA