LAUSANNE, Switzerland -- Under suspicion for doping, Roman Kreuziger has been denied his request to start the three-week Spanish Vuelta on Saturday.
The Court of Arbitration for Sport said it dismissed an urgent appeal by the Czech Republic rider, who remains provisionally suspended by the International Cycling Union while he is under investigation for possible doping in 2012.
Cycling's governing body said it was "pleased with the decision" to uphold the temporary ban it imposed this month.
"This decision is a recognition of the reliability of the athlete biological passport and the measures taken by the UCI to date in this case," it said in a statement.
The UCI believes long-term analysis of Kreuziger's blood values shows he was doping in 2012. He won a stage of the Giro d'Italia that season riding for the Astana team.
Kreuziger denies wrongdoing and has never tested positive for a banned substance or doping method, such as a blood transfusion.
The UCI added that "this is only a provisional suspension and that the hearing to decide on whether or not the rider has committed a doping offence will follow."
Now riding for Tinkoff-Saxo, Kreuziger was dropped from its Tour de France squad in June because of the ongoing case.
However, the team then selected him this month for the Tour of Poland because no formal disciplinary action had been taken.
The UCI intervened on the eve of the Polish stage race with a provisional suspension to keep Kreuziger sidelined.
The 28-year-old Kreuziger has three career top-10 finishes in the Tour de France and victories in the second-tier Tour of Romandie and Tour of Switzerland stage races. He also has a one-day classic victory, in the 2013 Amstel Gold race.