Two-time Grand Slam winner and former world number one Simona Halep has been banned from tennis for four years due to a doping violation.

The Romanian was provisionally suspended back in October after traces of roxadustat - a substance which increases haemoglobin and promotes the production of red blood cells - was found in her urine after the 2022 US Open.

Halep insisted that she would "fight to the end" to prove her innocence in the matter, and the former Wimbledon winner claimed that the quantity of roxadustat was "extremely low".

In addition, Halep argued that a contaminated supplement was the reason for her positive test, and she lashed out at the International Tennis Integrity Agency (ITIA) for "killing" her reputation, having allegedly seen her hearing pushed back on three occasions.

Nearly one year on from her provisional suspension, Halep has found guilty of two separate Tennis Anti-Doping Programme charges, with the second relating to her biological passport based on collection of 51 blood samples.

While the ITIA did accept Halep's claim that the roxadustat derived from a contaminated supplement, the agency concluded that the level of the banned substance "could not have resulted in the concentration of roxadustat found in the positive sample".

A panel of three Athlete Passport Management Unit (APMU) experts also investigated Halep's biological passport charge, and each member of the trio concluded that ""likely doping" was behind the irregularities.

As a result, the 31-year-old will not be allowed to compete until October 2026, having already served 11 months of her four-year suspension, which could potentially put the rest of her career in jeopardy.

ITIA CEO Karen Moorhouse said in a statement: "After a complex and rigorous hearing process, we welcome the independent tribunal's decision. The volume of evidence for the tribunal to consider in both the roxadustat and ABP proceedings was substantial.   

"The ITIA has followed the proper processes as we would with any other individual - in accordance with the World Anti-Doping Code - fulfilling our purpose and responsibility to uphold the principle of fair competition, on behalf of the sport. The panel recognised that appropriate procedure had been followed within the written decision. 
  
"We do understand the significant public interest in these cases and remain committed to being as transparent as possible and the full decision will be published in due course."

Halep - who won the 2018 French Open before defeating Serena Williams in the 2019 Wimbledon final - is free to appeal against the four-year ban, which is double the length of Maria Sharapova's initial suspension for failing a 2016 drug test.