Nairobi, Kenya (SportsNetwork.com) - Three-time Boston Marathon champion Rita Jeptoo has been handed a two-year ban from competition after testing positive for blood doping.

Athetics Kenya announced Friday that Jeptoo, who has won the last two Boston and Chicago Marathons and is the world's top-ranked female long-distance runner, was found to have used the prohibited blood-booster EPO in two separate samples.

The suspension became effective as of Oct. 30 and will run until Oct. 29, 2016. Jeptoo can appeal the penalty to the Court of Arbitration for Sport.

According to the Chicago Tribune, Jeptoo will have to forfeit her title at the most recent Chicago Marathon, which took place on Oct. 12. The International Track Federation told the newspaper that her suspension affects all results after Sept. 25.

Jeptoo also will have to give back her $500,000 purse as the winner of the 2013-14 World Marathon Majors series if the suspension is upheld.

The 33-year-old, one of Kenya's most recognizable athletes, set a course record of 2:18:57 in winning the Boston Marathon this past April.