When interviewed in April by the AIU, Chepngetich, the first woman to run a marathon in under 2:10, could not provide an explanation for the positive test.

While HCTZ has a minimum reporting level of 20 nanograms per millilitre (ng/mL) in urine, Chepngetich’s sample showed an estimated concentration of 3,800 ng/mL.

Traces of HCTZ below the minimal reporting level were also identified in a sample collected from Chepngetich two weeks earlier, on 28 February.

At a later interview on 11 July, Chepngetich was presented with the aforementioned suspicious evidence acquired from her phone. In the meantime, contamination had also been disproven by the AIU.

Chepngetich changed her explanation on 31 July, claiming that she had taken her housemaid’s medication – marked as being HCTZ – after becoming ill two days before the positive test.

The AIU had “serious reservations about the credibility of the new version of events” and, in the context of the sport’s anti-doping rules, such “recklessness” is considered “indirect intent, for which an increased four-year sanction applies”.

An automatic one-year reduction was applied after Chepngetich admitted the anti-doping rule violations within the 20 days required.

The three-year ban commenced on 19 April – when Chepngetich accepted a voluntary provisional suspension – with the athlete’s results, awards, titles, appearance and prize money since 14 March forfeited.

AIU chair David Howman said the case underlined that “nobody is above the rules”.

“While disappointing for those who put their trust in this athlete, this is how the system is supposed to work,” Howman said.

“The road-running industry should be commended for collectively funding anti-doping efforts capable of uncovering doping violations committed by elite athletes in their events.”