Cycling's governing body has asked Spanish authorities to open a doping case against 2010 Tour de France winner Alberto Contador.

The International Cycling Union says it wants the Spanish cycling federation to hold a disciplinary hearing regarding Contador's positive test for clenbuterol during the race.

The international cycling union conducted tests on the riders during the Tour de France, but national authorities prosecute doping cases. If found guilty, Contador would be stripped of the Tour de France victory and likely banned for two years.

The international body suspended Contador in September after his July 21 urine sample contained "very small" traces of the banned substance. Contador denies doping and says the clenbuterol came from contaminated meat.