Kenya's athletic confederation, Athletics Kenya, confirmed Friday that Rita Jeptoo, 33, tested positive again for EPO, a banned performance enhancing drug, according to CBS News.
Athletics Kenya said it conducted tests of the "B" sample between Wednesday and Friday at the World Anti-Doping Agency lab in Lausanne.
Jeptoo, three-time Boston marathon winner and two-time Chicago winner, will have a hearing for her case in January.
Her "A" sample tested positive in an out-of-competition test in Kenya in September for EPO, said vice presidents of Athletics Kenya, David Okeyo and Jackson Tuwei.
Jeptoo won her second straight title in Chicago on Oct. 12. She would have been crowned the winner of the World Marathon Majors series before the revelations about her doping tests.
Runner's World magazine said Jeptoo could face disqualification from the World Marathon Majors series with its $500,000 purse, and could face a two-year ban from competition.
Edna Kiplagat would receive the purse and the title, although Jeptoo has the right to appeal to the Court of Arbitration for Sport.
The Chicago win is the only competition Jeptoo performed in after her failed September drug test, and would be the only competition negated as a result of her "B" sample test.
Jeptoo's case will increase Athletics Kenya's cracking down on doping, according to Runner's World.
The federation has banned 32 athletes for doping in the past five years, CBS News reported.
