Kenya’s Diana Chepkorir slapped with four-year doping ban

AIU said the 23-year-old’s samples showed “abnormalities consistent with the use of a prohibited substance or method” between June and September 2024.

“The sequence of samples displays an ‘ON’ followed by an ‘OFF’ phase pathognomonic for situations where the red cell mass is artificially increased and the body subsequently downregulates its own red cell production to rebalance the amount of red cells to their normal level,” said AIU.

The athletes’ integrity watchdog confirmed that an Adverse Passport Finding was declared after three independent experts gave a unanimous opinion of “likely doping”.

Chepkorir, who is managed by Volare Sports, denied any wrongdoing and strongly criticised the process.

“I received your notice with utmost shock and disbelief… I disapprove of any involvement in any anti-doping violation.”

But the AIU rejected her defence, maintaining that all samples were properly handled and analysed by WADA-accredited laboratories.

The agency said Chepkorir failed to provide any scientific explanation for the abnormalities, leading to a formal charge in September and a provisional suspension effective from 15 September 2025.

“The AIU is comfortably satisfied that the Athlete has committed an Anti-Doping Rule Violation,” read the decision.

Chepkorir’s results from 25 June 2024 have been disqualified, with all medals and earnings forfeited.

She still has the right to appeal to the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland.

Chepkorir last competed at the Boulder 10km in the United States on May 26 this year. She began her career as a steeplechaser in 2016.

She becomes the fourth Kenyan athlete to be banned within the last one month by AIU for doping violation after Roncer Kipkorir Konga, Joyciline Chepngeno and Charles Kipkurui Langat, were all slapped with different bans.