PARIS (AP) -- A judicial official says the Paris prosecutor's office has opened a preliminary investigation into allegations of improper use of a controlled corticoid by cycling team Europcar during last year's Tour de France.

French sports daily L'Equipe first reported late Wednesday on details about the probe that began last August, the month after the 2011 Tour.

The judicial official, speaking on condition of anonymity because the case is ongoing, confirmed the probe to The Associated Press, but stressed that no evidence has been found.

The official said the case was opened after authorities received a notification from France's anti-doping agency, AFLD.

The case focuses on several riders on the French team.

The 2012 Tour begins on Saturday in Liege, Belgium.

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