Marathon champion Rita Jeptoo has been banned for two years after testing positive for the blood booster EPO, Athletics Kenya announced Friday.
A Sept. 25 out-of-competition blood test revealed traces of the banned substance.
Jeptoo went on to win the Chicago Marathon for the second time in October. She also has won the Boston Marathon three times, including last April.
Jeptoo's agent said in November that the runner denied any wrongdoing. But her “A” and “B” samples from September were positive.
She is barred from competition through Oct. 29, 2016, which means she'll miss this year's world championships in Beijing and next year's Summer Olympics in Rio de Janeiro.
The World Anti-Doping Agency has urged Kenya to improve its drug-testing program after dozens of the country's athletes have tested positive in recent years. Jeptoo is the biggest name to be caught up in the scandal.