Ruth Chepngetich exceeded the previous Tigst Assefa's female marathon global best by about two minutes at the marathon event in Chicago in 2024.
Female long-distance global champion the athlete has been suspended for three years after the Kenyan admitted to doping infractions.
The record holder was provisionally suspended in the seventh month following a positive test for Hydrochlorothiazide (HCTZ) - a banned diuretic often utilized as a concealing drug - on 14 March.
The athlete's achievements which occurred before that sample - such as her global best performance of 2:09:56 in Chicago in October 2024 - will still stand.
The sports governing body had sought a 48-month suspension but the 31-year-old punishment was reduced to three years because she admitted to the violations.
Nonetheless, the AIU will keep examining evidence from the athlete's phone which it found indicate "strong grounds that her positive test may have been deliberate" - featuring messages from as early as 2022.
"The case concerning the positive test for HCTZ has been resolved, but the unit will continue to investigate the suspicious material recovered from Chepngetich's phone to determine if any other violations have occurred."
When questioned in the fourth month by the integrity body, Chepngetich, the initial female to run a marathon in under 2:10, was unable to give an explanation for the positive test.
Although HCTZ has a lowest detectable limit of 20 nanograms per millilitre (ng/mL) in urine, Chepngetich's test showed an approximate level of 3,800 ng/mL.
Small amounts of HCTZ under the minimal reporting level were also identified in a test taken from the runner 14 days prior, on 28 February.
At a later interview on 11 July, Chepngetich was shown the aforementioned questionable proof acquired from her phone. In the meantime, accidental exposure had also been disproven by the AIU.
The athlete altered her story on July 31, stating that she had taken her domestic worker's medication - labeled as being the banned substance - after falling sick 48 hours prior to the positive test.
The AIU had "serious reservations about the credibility of the revised account" and, in the framework of the athletics' doping rules, such "carelessness" is deemed "indirect intent, for which an longer 48-month penalty applies".
An standard 12-month decrease was applied after Chepngetich admitted the anti-doping rule violations inside the specified 20-day period.
The 36-month suspension commenced on 19 April - when the athlete agreed to a voluntary provisional suspension - with the runner's results, awards, championships, participation and earnings since 14 March forfeited.
"No one is exempt from regulations."
"Although unfortunate for those who had faith in this runner, this is how the system is designed to operate."
"Marathon organizers should be commended for collectively funding anti-doping efforts capable of revealing doping violations committed by top competitors in their races."
