Daniel Wanjiru was banned on Wednesday for four years by the Athletics Integrity Unit after the 2017 London Marathon winner was found to have committed a doping violation.
Wanjiru, 28, was provisionally suspended in April for "use of a prohibited substance/method" after "abnormalities" were found in his biological passport.
The suspension has been backdated to start from December 9 last year.
All of his results from March 2019 "are disqualified with all resulting consequences including forfeiture of any medals, titles, ranking points and prize and appearance money", an AIU statement said.
As well as his 2017 triumph, Wanjiru also came eighth in the marathon at that year's world championships, also in London, and won the Amsterdam marathon in 2016.