Two-time Grand Slam champion Simona Halep has appealed to the Court of Arbitration for Sport (Cas) against her four-year doping ban.
An independent tribunal determined the Romanian, 32, had committed “intentional” anti-doping violations.
Halep said at the time she would “do everything in my power to clear my name of these false allegations.”
The former world number one has been suspended since 7 October 2022 after testing positive for Roxadustat.
“In her appeal to the CAS, the Athlete requests that the Challenged Decision be set aside and that her sanction be reduced,” a statement from the Swiss court read.
If her ban is upheld she will be able to play again on 7 October 2026, by which time she will be 35.
Cas, sport’s highest court, said the matter will be decided by a panel of arbitrators after a hearing and it was not yet possible to indicate a time frame for the decision.
Former world number one Halep tested positive for the use of Roxadustat at last year’s US Open, and was also found guilty of using an unspecified prohibited substance or method in 2022 after irregularities were found in her biological passport.
The tribunal accepted Halep’s argument she had taken a contaminated supplement, but decided that would not have resulted in the concentration of roxadustat found in her urine sample.
Roxadustat is an anti-anaemia drug which stimulates the production of red blood cells in the body.
“I take the rules that govern our sport very seriously and take pride in the fact I have never knowingly or intentionally used any prohibited substance,” Halep said in September.
“I refused to accept their decision of a four-year ban.”
Halep, who won the French Open in 2018 and Wimbledon the following year, is the highest-profile tennis player to fail a drugs test since Maria Sharapova in 2016.
She has won 24 WTA tour singles titles and earned £32.2m ($40.2m) in prize money and was ranked number one in the world in 2017 and 2018.