Jepchirchir tested positive for banned blood booster EPO in a sample taken before her Sydney Marathon win in August. By Pearl Josephine Nazare Oct 23 (Reuters) - Kenya's world marathon champion Peres Jepchirchir has been provisionally suspended after testing positive for the banned blood booster EPO in a. Athletics Integrity Unit says Olympic gold medalist tested positive for banned substance EPO in sample collected before Sydney Marathon victory |.