A two-year ban and the loss of this year Tour de France title looms as a possible penalty for Span's Alberto Contador after cycling governing body the UCI asked the Spanish federation to take disciplinary measure against him for failing a drugs test.
The 27-year-old tested positive for the banned stimulant clenbuterol on the second rest day of this year's Tour which he won for the third time, beating Luxembourg's Andy Schleck by 39 seconds.
Contador claims the traces of the banned substance were from contaminated meat he ate, prompting the UCI and World Anti-Doping Agency to investigate the matter further.
The UCI says a WADA investigation concluded that disciplinary proceedings should be taken and its now the responsibility of the Spanish Federation to determine whether Contador breached anti doping rules.
The Spanish federation can decide whether to ban Contador, who has been provisionally suspended by the UCI, or to clear him.
If the federation decides not to sanction the world's top rider, the UCI and WADA can take the matter to the Court of Arbitration for Sport.