Two-time major winner Simona Halep has been provisionally suspended after testing positive for a banned substance, the International Tennis Integrity Agency (ITIA) said.
The former world number one said being notified of the adverse finding was "the biggest shock of my life".
Currently ninth in the WTA rankings, Halep confirmed she has tested positive for Roxadustat, a prohibited anti-anemia drug recently approved for medical use in the European Union.
According to the EU’s medicines agency, which approved Roxadustat last year, it stimulates the body to produce more of the natural hormone erythropoietin, or EPO.
EPO has long been a doping product favoured by cyclists and distance runners owing to its ability to enhance the production of red blood cells and improve the flow of oxygen to muscles.
During a provisional suspension, a tennis player is ineligible to compete in, or attend, any sanctioned events.
"Simona Halep, a 31-year-old Romanian tennis player, has been provisionally suspended under Article 7.12.1 of the 2022 Tennis Anti-Doping Programme," the body said in a statement.
The ITIA said the sample was returned during the US Open, where Halep was knocked out in the first round by Ukranian qualifier Daria Snigur.
Halep, 31, has not played on the tour since, previously announcing she was ending her season to have surgery on her nose.
The 2019 Wimbledon champion said she feels "confused and betrayed" by the result.
"Today begins the hardest match of my life: A fight for the truth," Halepwrote in a statement on Twitter.
"Throughout my whole career, the idea of cheating never even crossed my mind once, as it is totally against all the values I have been educated with.
"Facing such an unfair situation, I feel completely confused and betrayed.
"I will fight to the end to prove that I never knowingly took any prohibited substance and I have faith that sooner or later, the truth will come out."
As well as Wimbledon, Halep won the 2018 French Open and was a finalist at the Australian Open the same year.
She was the first Romanian woman to be ranked number one in the world, a crown she held from October 2017 to January 2019.
Halep was voted as the WTA Fan Favourite three years in a row from 2018 to 2020.
The Romanian faces a ban of up to four years if found guilty by the World Anti Doping Agency, WADA.
ABC/Reuters
