Kenya’s world marathon champion Peres Jepchirchir has been provisionally suspended after testing positive for the banned blood booster EPO in a sample taken before her Sydney Marathon victory, the Athletics Integrity Unit (AIU) said.

The AIU added that the out-of-competition sample collected in Kenya returned an adverse analytical finding for EPO (erythropoietin), which boosts the production of red blood cells.

“I can only say that I feel terrible about what happened and I think it’s only right that an athlete who uses performance enhancing drugs should be disqualified,” her agent Gianni Demadonna said in an emailed statement.

Sydney Marathon organisers said they were “extremely disappointed” to learn about Jepchirchir’s provisional suspension.

“Jepchirchir is entitled to due process and we will make no further comment on the case until that process has concluded,” organisers said in a statement on social media.

“Our commitment to clean sport is unwavering. Every athlete who lines up in Sydney deserves to race on a level playing field and every participant and spectator deserves to trust the result they see at the finish line.

“That conviction is why, alongside our fellow Abbott World Marathon Majors, we have invested in increased out-of-competition testing in partnership with the AlU, and why we will keep standing firmly with the athletes who compete cleanly.”

The 33-year-old is a former Olympic champion and half-marathon world record holder, as well as a four-time World Marathon Majors winner.

She won gold at the Tokyo Games in 2021 and has also claimed major marathon victories in New York (2021), Boston (2022), London (2024) and Sydney (2026).

Jepchirchir dominated the women’s race in Sydney in August, pulling clear of the field to finish in 2:18:31, more than three minutes ahead of second-placed compatriot Irine Cheptai.

Last year, Kenya’s women’s marathon world record holder Ruth Chepngetich was banned for three years after admitting anti-doping rule violations involving hydrochlorothiazide (HCTZ), a prohibited diuretic, though her world record of 2:09:56 remained on the books because it was set before her positive test.