Cycling's governing body UCI said Thursday that it would appeal to the Court of Arbitration for Sport against Spain's decision to acquit rider Alberto Contador from doping charges.

"The International Cycling Union today decided ... to appeal to the Court of Arbitration for Sport in Lausanne against the Spanish Cycling Federation's finding in the case of Alberto Contador," said the UCI in a statement.

"He was acquitted after testing positive for clenbuterol during an in-competition test carried out on 21st July 2010," added the statement.

Three-time Tour de France winner Contador tested positive for a small amount of the banned muscle-building substance clenbuterol during last July's Tour.

However, he was cleared to compete when the Spanish cycling federation last month rescinded proposals to hand down a one-year competition ban. It accepted the rider's claim that he had eaten drug-contaminated meat and was therefore not negligent.