Olympic champion runner Caster Semenya appealed Wednesday against a decision by sport's highest court to uphold highly contentious new rules in track and field that force her to take testosterone-suppressing medication or have surgery in order to compete in female races at top international events.

Semenya's appeal against this month's ruling by the Court of Arbitration for Sport in Switzerland will be heard by the Swiss Federal Tribunal, the country's supreme court. The two courts sit about 400 meters apart in the city of Lausanne.

Semenya's appeal focuses on "fundamental human rights,'' her lawyers said in a statement. The appeal asks the Swiss Federal Tribunal to set aside the CAS decision to allow the sport's governing body to set limits on natural testosterone "in its entirety.''

The 28-year-old Semenya, who is from South Africa, lost her case against international track body the IAAF on May 1. It meant she and other women with one of a specific group of medical conditions known as differences of sex development (DSD) must medically lower their natural testosterone levels to a point specified by the IAAF to be able to run in the Olympics, world championships and other international track meetings.

Athletes affected by the rules have levels of testosterone in the male range, the IAAF says, and they must reduce them to be allowed to run in women's events. The IAAF argues that testosterone's muscle-building capacity and ability to help athletes carry more oxygen in their blood gives Semenya and others like her an unfair athletic advantage over other women.

The rules, which came into effect May 8, apply to races from 400 meters to one mile. That means Semenya, who is a two-time Olympic champion and three-time world champion in the 800 meters, is currently not allowed to run her favorite race unless she takes medication or has surgery. She was due to defend her title at the world championships in Doha, Qatar in September.

Semenya said in the days after CAS ruling that she would not take the drugs recommended by the IAAF to alter her natural testosterone and she repeated her stance Wednesday.

"I am a woman and I am a world-class athlete," Semenya said. "The IAAF will not drug me or stop me from being who I am."

CAS decisions can be appealed to Switzerland's supreme court on only a very limited number of grounds. One of them is that a ruling violates a person's human rights.

"The IAAF regulations violate the most fundamental principles of Swiss public policy," said Dorothee Schramm, the lawyer in Switzerland who will lead Semenya's appeal. "In the race for justice, human rights must win over sporting interests."

Semenya's lawyers added the appeal would ask the supreme court "to consider whether the IAAF's requirements for compulsory drug interventions violate essential and widely recognized public policy values, including the prohibition against discrimination, the right to physical integrity, the right to economic freedom, and respect for human dignity."

The lawyers could also seek a temporary suspension of the IAAF rules to allow Semenya to defend her 800 title at the worlds in Doha. Appeals to the Swiss Federal Tribunal are typically lengthy cases, with some taking a year or more to be decided.

Semenya has battled track authorities for the right to run in what she describes as her natural form for a decade, ever since she was subjected to gender verification tests by the IAAF at the age of 18 when she won her first major title in 2009.

The dispute is viewed as one of the most controversial and complex to face sport and it could lead to similar rules being introduced by other sporting bodies. It also has implications for all levels of sport.

While many sports split up competitions into male and female divisions, leading medical organizations generally believe that sex and its characteristics do not always fall neatly into one of two categories.

The IAAF rules apply to female athletes with certain differences of sex development and specifically those born with the typical male XY chromosome pattern. The athletes must also have testosterone levels higher than the typical female range, which the IAAF argues gives them their unfair athletic advantage.

To compete in the Olympics, world championships or other international track and field events, each athlete must reduce her testosterone level and keep it within the acceptable range for six months prior to competing. The IAAF gives three medical options: a daily contraceptive pill, a monthly testosterone-blocking injection or surgery. The treatments could inhibit athletic performance but by how much is uncertain, while also posing risks of other negative side effects.

The treatment has been labeled as unethical by an array of experts, including the World Medical Association, which represents doctors across the world.

Athlete medical records and details of DSD tests are confidential, but Semenya and Indian sprinter Dutee Chand have fought testosterone regulations. Two other runners, Francine Niyonsaba of Burundi and Margaret Wambui of Kenya, have recently said publicly that they would be affected by the new testosterone rules. Niyonsaba won the silver medal behind Semenya in the 800 meters at the 2016 Olympics in Rio de Janeiro and Wambui won the bronze.

It's unclear how many others are affected. The IAAF says it will not identify athletes with DSD but says there are numerous and "the majority'' of them compete in the races covered by the rules.