Two-times major winner Simona Halep of Romania has been provisionally suspended after testing positive for the banned blood-booster roxadustat, the International Tennis Integrity Agency (ITIA) said on Friday.

Halep, ranked ninth in the world, was tested during the U.S. Open and both her A and B samples confirmed the presence of roxadustat, an anti-anaemia drug that stimulates the production of red blood cells much like the prohibited substance Erythropoietin (EPO).

"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 (TADP)," the body said in a statement.

"The sample was split into A and B samples and the subsequent analysis found that the A sample contained FG-4592 (Roxadustat), which is a prohibited substance listed in the 2022 World Anti-Doping Agency (WADA) Prohibited List."

The 2019 Wimbledon champion later requested for her B sample to be analysed, which confirmed the initial findings.

Former world number one Halep described the ban as the "biggest shock of her life" and denied knowingly taking any banned substance.

"Today begins the hardest match of my life: a fight for the truth. I have been notified that I have tested positive for a substance called Roxadustat in an extremely low quantity, she wrote 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."

Halep, who also won at Roland Garros in 2018, added that her fight was not about "titles or money" but her honour and she hoped that the truth would eventually come out.

Maria Sharapova was the last high-profile tennis player to be involved in a doping scandal after the Russian tested positive for meldonium at the 2016 Australian Open and was initially banned for two years before it was reduced to 15 months.

Halep's suspension means that she cannot compete in or attend any sanctioned events organised by the governing bodies of the tennis.

Halep, the winner of two titles this season, ended her season early after undergoing nose surgery last month to treat breathing difficulties.

(Reporting by Dhruv Munjal in Bengaluru; Editing by Frank Jack Daniel and Pritha Sarkar)