Paris - Twelve cyclists, including the race winner, tested positive for the banned blood booster EPO during last month's Tour of Costa Rica, the UCI announced on Wednesday.
The doping controls were carried out by the Cycling Anti-Doping Foundation, an independent body in charge of overseeing the sport's anti-doping strategy, with the assistance of Costa Rican sports authorities.
Juan Carlos Rojas Villalegas, who won the 10-stage event, was among those notified of an adverse analytical finding.
Eleven of the 12 riders implicated returned positive tests for the third-generation blood booster EPO-CERA, while the other provided a sample with EPO.
The group has been provisionally suspended until the matter is resolved.