Former number one in women’s tennis, Simona Halep, took her appeal against a four-year doping suspension to the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland on Wednesday.

The hearing, which is expected to span three days, comes after Halep was penalized last September by the International Tennis Integrity Agency (ITIA) following two doping violations.

Halep, who has won two Grand Slam singles titles, was found positive for the banned substance roxadustat following her participation in the 2022 US Open. Additionally, she faced charges last year for another anti-doping rule violation concerning anomalies in her athlete biological passport.

Accompanied by her legal representation, a composed Halep arrived at the CAS’s headquarters located in the Palais Beaulieu, Lausanne, but declined to comment on the proceedings. The date for the CAS’s decision on her appeal remains to be determined.

The Romanian tennis star has consistently maintained her innocence, challenging the ITIA’s ruling which currently bars her from professional tennis until October 6, 2026. Halep, victor of the French Open in 2018 and Wimbledon in 2019, has expressed her determination to “clear her name,” citing expert analysis that purportedly identified accidental consumption of a contaminated supplement as the cause of her positive test.

However, the ITIA contended that, although the tribunal recognized the ingestion of a contaminated supplement by Halep, the amount she consumed could not account for the level of roxadustat detected in her system.

Roxadustat is known to treat anemia but is prohibited under the World Anti-Doping Agency’s list of banned substances due to its potential for blood doping, enhancing haemoglobin, and red blood cell production. The athlete biological passport system aims to detect doping by monitoring variations in an athlete’s blood profile over time.