The Athletics Integrity Unit described the infractions as "exceptionally severe," with the ban retroactively starting from 8 August, 2023, and extending until 2029. All of Kwemoi's performances from 18 July, 2016, to August of the previous year have been invalidated.

At the age of 27, Kwemoi notably clinched victory at the world junior championships in Bydgoszcz in 2016 and secured a bronze medal in the 10,000m event at the Commonwealth Games on the Gold Coast in 2018.

His track record includes a fourth-place finish at the Doha world championships in 2019, a seventh-place position in the same event at the Tokyo Olympics, which were postponed due to Covid, in 2021, and a 15th-place finish at the 2022 world championships in Eugene.

The AIU's expert panel reported that Kwemoi's athlete biological passport (ABP) revealed 18 instances of blood doping "spanning over an extended period of more than six years, indicating the use of a prohibited substance or method on multiple occasions."

"Most of these manipulations occurred in the lead-up to major athletics competitions," the panel elaborated. "The athlete was involved in a deliberate, systematic, and sophisticated doping regimen. Such actions could not have been executed without deliberate intent and the aid of experts."

Residing in Japan, Kwemoi argued that the ABP irregularities were due to changes in climate and altitude, but the panel dismissed his explanation. Kenya, known for its outstanding middle and long-distance runners, has experienced a series of failed drug tests in recent years. 

Nearly 100 Kenyan athletes, predominantly long-distance runners, have been banned over the last five years.