Nairobi - Kenya's Olympic marathon champion Jemima Sumgong has been suspended for four years for doping, Athletics Kenya said Tuesday.
"Sumgong will serve the four-year ban as from (April 3) when she was provisionally suspended," Athletics Kenya said in a statement.
The 32-year-old tested positive for the banned blood booster EPO in an out-of-competition test by the International Association of Athletics Federations (IAAF) in her native Kenya.
Erythropoietin is a natural hormone that stimulates red cell production. For a runner, injecting an artificially produced version increases oxygen absorption which allows them to run harder and faster without tiring.
Sumgong, who also tested positive for a banned substance in 2012, starred at the London Marathon in 2016, defying the odds to win despite suffering a bruising fall.
Steeled by her success in London, she then became the first Kenyan woman to win Olympic marathon gold, defeating Ethiopia's world champion Mare Dibaba in Rio to confirm her status as the world's top marathon runner of 2016.
Due to her suspension she was unable to defend the titlein London this year.
Earlier this year, Sumgong was one of a number of top Kenyan athletes who welcomed a new initiative to eradicate doping, which has tarnished their image, agreeing to be monitored by doctors appointed by the IAAF and Athletics Kenya.
"It will be easy for us now to communicate with these doctors before we take any medicine when the need arises," said Sumgong.
The move came after an investigation by German television channel ARD and Britain's Sunday Times newspaper last July alleging that doping was rife at the elite training centre in Iten.
Kenyan athletics boss chief Jackson Tuwei warned that any athlete who failed to comply would not be selected to represent the country in international competitions.
"Forty-nine athletes have been found to have violated the WADA (World Anti-Doping Agency) code in the past five years but were cautioned according to the laws of the land and WADA code," he said earlier this year.
Sumgong's former training partner, the 2014 Chicago and Boston Marathon champion Rita Jeptoo, is serving a four-year ban after also testing positive for EPO.
In 2012 Sumgong tested positive for steroid Prednisolone following the Boston marathon. She only served half of a two year ban after a successful appeal blamed the failed control on treatment for a hip injury.