Champion runner Caster Semenya won a potentially landmark legal victory on Tuesday when the European Court of Human Rights decided she was discriminated against by sports rules that force her to medically reduce her natural hormone levels to compete in major competitions.

The ruling by the Strasbourg, France-based court questioned the “validity” of the contentious international athletics regulations in that they infringed Semenya’s human rights.

But the two-time Olympic champion’s first legal success after two failed appeals in sports’ highest court and the Swiss supreme court came with a major caveat. Amid her bid to be allowed to run again without restriction and go for another gold at next year’s Olympics in Paris, Tuesday’s judgment, while major, did not immediately result in the rules being dropped.

That might still take years.

The South African athlete’s challenge against the testosterone rules began in 2018.

It has gone from the Switzerland-based Court of Arbitration for Sport to the Swiss supreme court and now the European rights court. The 4-3 ruling in Semenya’s favor by a panel of human rights judges merely opened the way for the Swiss supreme court to reconsider its decision.

That might result in the case going back to CAS in Lausanne. And only then might the highly controversial rules enforced by World Athletics be possibly removed.

The 32-year-old Semenya, who has been barred by the rules from running in her favorite 800-meter race since 2019 and has lost four years of her career at her peak, has only 13 months until Paris.

In a statement soon after the European rights court’s decision was published, World Athletics showed no sign of budging and said its rules would “remain in place.”

“We remain of the view that the … regulations are a necessary, 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,” World Athletics said.

World Athletics also said it would be “encouraging” the government of Switzerland to appeal the ruling. Switzerland was the respondent in the case because Semenya was challenging her last legal loss in the Swiss supreme court. Switzerland’s government has three months to appeal.

The Swiss government was also ordered to pay Semenya 60,000 euros ($66,000) for costs and expenses.

There was no immediate reaction from Semenya or her lawyers in South Africa.

While Semenya has been at the center of the highly emotive issue of sex eligibility in sports and is the issue’s figurehead in challenging the rules, she is not the only athlete affected. At least three other Olympic medalists have also been impacted by the rules that set limits on the level of natural testosterone female athletes may have if they want to compete. World Athletics says there are “a number” of other elite athletes who fall under the regulations.

There are no testosterone limits in place for male athletes.

Semenya’s case is not the same as the debate over transgender women who have transitioned from male to female being allowed to compete in sports, although the two issues do have crossover.

Semenya was identified as female at birth, raised as a girl and has been legally identified as female her whole life. She has one of a number of conditions known as differences in sex development, or DSDs, which cause naturally high testosterone that is in the typical male range.

Semenya says her high natural testosterone should be considered a genetic gift in the same way as a basketballer’s height or a swimmer’s long arms.

While track authorities can’t challenge Semenya’s legal gender, they say her condition includes her having the typical male XY chromosome pattern and physical traits that make her “biologically male,” an assertion that has enraged Semenya. World Athletics says Semenya’s testosterone levels give her an athletic advantage that is comparable to a man competing in women’s events and there needs to be rules to address that.

To do that, track has enforced rules since 2019 that require athletes like Semenya to artificially reduce their testosterone to below a specific mark, which is measured through the amount of testosterone recorded in their blood. They can do that by taking daily contraceptive pills, having hormone-blocking injections, or undergoing surgery under the rules. If athletes choose one of the first two options, they would effectively need to do it for their entire careers to remain eligible to compete regularly.

Semenya has railed against the regulations, and refused to follow them since 2019, saying they discriminated against her because of her condition.

On Tuesday, the European Court of Human Rights agreed. It also found for Semenya on another point of her appeal, that she wasn’t given “effective remedy” against that discrimination when the Court of Arbitration for Sports and the Swiss supreme court both denied her appeals.

There were “serious questions as to the validity” of the testosterone rules, the court said, including with any side effects of the hormone treatment athletes would have to undergo, the difficulties in them remaining within the rules by trying to control their natural hormone levels, and the “lack of evidence” that their high natural testosterone actually gave them an advantage anyway.

That last point struck at the heart of the regulations, which World Athletics has always said is about dealing with the unfair sports advantage Semenya has over other women.

The European rights court also found Semenya’s second legal appeal against the rules at the Swiss supreme court should have led to “a thorough institutional and procedural review” of the rules, but that did not happen.

The rules have been made stricter since Semenya launched her case at the European rights court, with World Athletics announcing in March that athletes would have to reduce their testosterone level to an even lower mark. The updated regulations also apply to every event and not just Semenya’s favored range between 400 meters and one mile, which they did previously.