The doping case against Mo Trafeh has taken a new turn with an arbitrator imposing a four-year ban against the distance runner.
According to the U.S. Anti-Doping Agency, the arbitrator found that Trafeh had used the banned substance EPO on numerous occasions. He has been stripped of all results -- including a record-setting 25-kilometer national championship -- dating back to 2012.
Authorities caught Trafeh with EPO at an airport earlier this year. Though he never failed a test, the USADA built a case against him with witness testimony and other documentary evidence.
"This decision by the independent arbitrator shows the importance of non-analytical case in the effort to protect clean athletes," the anti-doping agency's chief executive, Travis T. Tygart, said.
Born in Morroco, Trafeh became a U.S. citizen in 2008. He has denied any wrongdoing and recently announced his retirement, saying he could not afford the legal costs of contesting his case.
EPO is a synthetic hormone that stimulates red-blood cell production. Its use can improve aerobic performance.