COLORADO SPRINGS, Colo. (AP) — Road racing champion Mo Trafeh has received a four-year doping ban for using EPO and will have to forfeit three of his U.S. championships.

The Moroccan-born U.S. citizen announced his retirement earlier this year, saying he had purchased blood-boosting EPO but had never used it.

An investigation by the U.S. Anti-Doping Agency concluded Trafeh had used the drug and had also evaded sample collectors. An independent arbitrator upheld the USADA ruling, meaning Trafeh will give up his 2012 national title and his 2013 titles in the half marathon and 25K.

The arbitrators called for the start of the four-year suspension to date retroactively, to January 2012. USADA is considering an appeal to make the official start date Dec. 2, 2014 — the day the arbitration panel issued the decision.