Kenyan marathon star Peres Jepchirchir has been provisionally suspended by the Athletics Integrity Unit (AIU) after testing positive for erythropoietin (EPO), a banned substance that stimulates the production of red blood cells and can enhance endurance performance.

According to the AIU, the adverse analytical finding came from an out-of-competition sample collected in Kenya before Jepchirchir won the Sydney Marathon on August 30, 2026.

The development has cast uncertainty over the achievements of the 33-year-old athlete, who is a former Olympic champion, half-marathon world record holder and four-time winner of World Marathon Majors events.

Jepchirchir’s agent, Gianni Demadonna, expressed disappointment over the case, saying athletes who use performance-enhancing substances should face disqualification.

“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,” Demadonna said in an emailed statement.

Organisers of the Sydney Marathon also expressed disappointment over the announcement but emphasised that the athlete must be allowed to go through the established disciplinary process.

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

They reaffirmed their commitment to clean sport, stressing the importance of fair competition and protecting athletes who compete without using prohibited substances.

EPO increases the production of red blood cells, improving the blood’s ability to transport oxygen to muscles. Its use is prohibited in athletics because it can provide an unfair competitive advantage and pose serious health risks.

Jepchirchir’s provisional suspension marks a significant development in international distance running, given her status as one of Kenya’s most accomplished marathon athletes.

However, the suspension is not a final determination of an anti-doping violation. The case remains subject to the applicable disciplinary process, and further decisions will determine its implications for her career and the results under review.

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