The 33-year-old South African athlete won a long legal battle last July against Switzerland at the ECHR, which ruled she was the victim of discrimination from the Lausanne-based Court of Arbitration for Sport.
But Swiss authorities, supported by track and field's governing body World Athletics, have taken the matter to the ECHR's Grand Chamber, whose rulings are binding, with hearings now slated to start on May 15.
Semenya, who is classed as having "differences in sexual development (DSD)" but has always been legally identified as female, has refused to take drugs to reduce her testosterone levels since World Athletics introduced the original rules in 2018.
As a result, the Olympic 800m champion in 2012 and 2016 and world gold medallist in 2009, 2011 and 2017, has been barred from competing at her favored two-lap distance and was forced to make an unsuccessful move up to 5,000m.
FILE—South Africa's Caster Semenya reacts after finishing the women's 5000m final of the 22nd African Athletics Championships at the Cote d'Or National Sports Complex in Saint Pierre, on June 9, 2022.
The ruling by the ECHR last July was largely symbolic as it does not call into question the World Athletics ruling and does not pave the way for Semenya to return to competition without taking the medication.
In her book, "The Race To Be Myself," Semenya confessed that her career at the top was over. She said she was now focused on being an advocate for young athletes facing similar challenges.
World Athletics introduced the DSD regulations to create a level playing field in women's events.
Semenya failed to reach the 5,000m final at the 2022 world championships in Eugene.
Last year, World Athletics amended its rules and DSD athletes like Semenya now have to reduce their amount of blood testosterone to below 2.5 nanomoles per liter, down from the previous level of five, and remain below this threshold for two years.
World Athletics also removed the principle of restricted events for DSD athletes, meaning that they are barred from all distances unless they meet the testosterone criteria.