Kenyan marathon runner Brimin Kipkorir has been provisionally suspended after he tested positive for prohibited substances, the Athletics Integrity Unit (AIU) said on Monday.
Kipkorir won the Sydney Marathon in 2024 in a course record time of 2:06:18 and the Frankfurt Marathon in 2022 and 2023.
"The AIU has provisionally suspended Brimin Misoi Kipkorir (Kenya) for the Presence/Use of Prohibited Substances (EPO, Furosemide)," the AIU said in a statement.
"This sample was collected out-of-competition on November 22 2024."
Marathon running has been hit with a spate of high-profile doping cases in recent years, particularly from powerhouse Kenya.
Kenya's Diana Kipyokei was stripped of her 2021 Boston Marathon title for doping in 2022 and handed a six-year ban.