The Kenyan tested positive for the steroid Nandrolone at races in Guatamala on Jan. 26 and in Mexico on March 2, which made her ineligible to compete in Calgary's marathon June 1, the Calgary Marathon Society said Thursday in a statement.
Her two-year suspension ends April 5, 2016.
The IAAF, which is the world's governing body of track and field, announced last week that Chepkorir was among eight Kenyan runners guilty of major doping violations.
The top three finishers in the women's marathon have been re-distributed with Calgarian Maria Zambrano winning in a time of two hours 52 minutes 44 seconds
Nadine Mueller of Canmore, Alta., was second in 2:59.59 and Andrea Glover of Nanton, Alta., finished third in 3:01.29.
"We regret the proper winners didn't get the recognition they deserved in the moment," Calgary Marathon Society chairman Dan Ouimet said in the statement.
"Unfortunately doping is a part of all sports, at all levels and Calgary Marathon has evolved to a big-city destination race offering a competitive prize purse and attracting international elite athletes.
"To ensure excellence of future championship races, including the 21.1K national championships being hosted in conjunction with the Scotiabank Calgary Marathon Race Weekend, elite runners may be subject to drug testing in 2015."
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