World marathon record-holder Ruth Chepng’etich has been banned from competition for three years after admitting to violating anti-doping rules, the Athletics Integrity Unit (AIU) announced on Thursday.

The 31-year-old Kenyan athlete tested positive for the banned diuretic Hydrochlorothiazide (HCTZ) in a sample collected on March 14, 2025. The AIU said its investigation confirmed the presence of the substance in her urine.

“Women’s marathon world record-holder, Ruth Chepng’etich, has been banned for three years after admitting to Anti-Doping Rule Violations regarding the presence and use of Hydrochlorothiazide,” the AIU said in a statement.

HCTZ is commonly prescribed to treat high blood pressure but is prohibited in athletics because it can be used to mask the presence of other banned substances. While the drug itself is not automatically banned, the World Anti-Doping Agency (WADA) imposes strict limits on its use by professional athletes.

Chepng’etich, who set the women’s marathon world record with a 2:11:53 finish in Chicago in 2023, was first questioned by investigators in April 2025. She initially denied any wrongdoing, saying she could not explain the positive result.

Investigators searched her supplements, medications, and mobile phone for clues, but all samples tested negative for prohibited substances. When she was re-interviewed in July, data from her phone raised fresh concerns that the positive test may not have been accidental.

Under mounting pressure, Chepng’etich altered her account, saying she had mistakenly taken her domestic manager’s medication two days before the test, unaware it contained a banned substance.

The AIU, however, dismissed this explanation as “not credible,” citing reckless disregard and indirect intent to dope — grounds for a standard four-year ban.

Her early admission and acceptance of the sanction earned her a one-year reduction, resulting in a three-year suspension.

The ban is a dramatic fall from grace for one of Kenya’s most celebrated athletes. Chepng’etich had become a symbol of endurance and dominance, claiming three consecutive Chicago Marathon titles and shattering records that once seemed untouchable.

Her case now adds to a growing list of Kenyan runners under scrutiny for doping, a challenge that has put the country’s famed distance-running reputation under intense global focus.

The AIU said Chepng’etich’s suspension takes effect from March 2025, meaning she will not be eligible to compete until 2028.