As a result of her DSD, she has been banned from participating in track events without taking testosterone-reducing medication.
The European Court of Human Rights (ECHR) has decided in favour of double 800m Olympic champion Caster Semenya, addressing a prolonged dispute concerning testosterone levels in female athletes.
South African athlete Semenya, 32, was born with differences of sexual development (DSD).
As a result of her DSD, she has been banned from participating in track events without taking testosterone-reducing medication.
This mandate stems from regulations introduced by World Athletics in 2018, despite the athlete's arduous legal attempts to overturn this ruling.
Semenya, an illustrious figure in athletics, boasts a glittering career as a three-time 800m world champion and both 800m and 1500m Commonwealth champion.
The recent ruling provides a crucial legal victory for her following an enduring struggle with World Athletics.
Notably, the case deliberated upon by the ECHR was not targeted at sports bodies or DSD regulations.
Instead, it held the Swiss government accountable for failing to safeguard Semenya's rights.
The case harks back to a Swiss Supreme Court decision three years prior, which the ECHR concluded failed to protect Semenya from discrimination.
The court said in a statement that Semenya "had not been afforded sufficient institutional and procedural safeguards in Switzerland" to allow her to "have her complaints examined effectively, especially.
It added that “since her complaints concerned substantiated and credible claims of discrimination as a result of her increased testosterone level caused by differences of sex development."
The ruling also suggested that the particular World Athletics regulations were discriminatory to Semenya "by the manner in which they were exercised and by their effects".
The CAS had previously acknowledged that the testosterone rules for athletes like Semenya were discriminatory.
However, they justified the discrimination as "necessary, reasonable, and proportionate" to maintain the integrity of female athletics.
Meanwhile, World Athletics said: "We remain of the view that the DSD regulations are a necessary.”
“They are reasonable and proportionate means of protecting fair competition in the female category as the Court of Arbitration for Sport and Swiss Federal Tribunal both found, after a detailed and expert assessment of the evidence.”
DSD rules explained - BBC
Under regulations introduced in 2018, athletes with DSD were only allowed to compete in track events between 400m and the mile if they reduced their testosterone levels.
However, in March World Athletics ruled that DSD athletes must now have hormone-suppressing treatment for six months before being eligible to compete in all events.
Semenya ran in the 5,000m at last year's World Championships in Oregon but failed to qualify for the final.
She has argued that taking testosterone-reducing medication could endanger her health and that the ruling denied her and other athletes with DSD the right to rely on their natural abilities.
Because of the ruling, she could not defend her 800m title at the Tokyo Olympics, which took place a year later than planned in 2021.
Semenya, who has always been legally identified as female, has said she should be able to compete in women's events even if her testosterone levels are higher than her competitors.
In 2019 she told BBC Sport she had been "crucified" but will "never stop fighting" against the regulations brought in by World Athletics, then known as the IAAF.