NAIROBI, Kenya — Athletics Kenya said on Friday it has banned marathon champion Rita Jeptoo two years for doping.

Jeptoo has won the Boston Marathon three times, and her second Chicago Marathon in October. She finished fourth in the 2012 Beach to Beacon race.

But traces of the banned blood-booster EPO were found in her out-of-competition test in Kenya on Sept. 25.

Jeptoo is the biggest name among several Kenyan athletes who have failed drug tests in recent years.

She tested positive for the blood-booster EPO in an out-of-competition test conducted last September before she went on to defend her Chicago title the following month. Both the “A” and “B” samples were positive.

Jeptoo’s estranged partner, Noah Busiendich, Italian manager Federico Rosa and Italian coach Claudio Berardelli also appeared before the disciplinary commission.

Under the previous World Anti-Doping Code, the standard sanction for a serious doping offense was a two-year ban. The punishment has been doubled to four years under the new version of the code, which went into effect on Jan. 1.

Jeptoo testified for more than two hours before a Kenyan disciplinary commission.

The 33-year-old Jeptoo looked down and made no comment to reporters as she entered and left the Athletics Kenya headquarters.

Jeptoo has already been denied her share of the $500,000 prize for winning the 2013/14 World Marathon Majors.

Rosa maintained his Rosa Associati firm had nothing to do with the athlete’s use of EPO.

“I wanted to clear my company here,” he said. “Let the committee meet and make a statement but my relationship with Jeptoo ended the moment she tested positive. I have nothing to do with people who dope.”

Berardelli, the coach who has also handled world and Olympic champions, also distanced himself from Jeptoo.

“A lot of negative things have been told about me following something I had nothing to do with or knew, but I love Kenyan athletes and I will continue working with them,” he said.