MONACO (AP) — Olympic and world marathon champion Peres Jepchirchir has been provisionally suspended over a positive drug test for the banned substance EPO, the Athletics Integrity Unit said Friday.

Jepchirchir won women's marathon gold at the Tokyo Olympics in 2021 and the world title last year. The 33-year-old Kenyan runner is also a former world record holder in the half marathon.

The AIU, which investigates doping in track and field on behalf of the sport's governing body World Athletics, posted on X that “an out-of-competition sample, collected in Kenya prior to her recent Sydney Marathon victory, returned an adverse analytical finding for EPO.”

Jepchirchir won the Sydney Marathon in August. Her representative Gianni Demadonna declined to comment when contacted by The Associated Press.

It's the latest in a long series of doping cases involving distance runners from Kenya, which was awarded the 2029 world track championships last month.

Women's marathon world record holder Ruth Chepng’etich, who is also from Kenya, was banned for three years in 2025 after admitting a charge related to a positive test for a banned diuretic. Former New York Marathon winner Albert Korir was given a five-year ban in March.