Spanish cyclist Alejandro Valverde announced on Wednesday that he is bringing a lawsuit against Italian Olympic Committee (CONI) anti-doping prosecutor Ettore Torri.
"Mr Torri acts, in a repeatedly obstinate manner, with total disregard for the Spanish legal authorities, refusing to submit to the decision of the Madrid judge that forbids CONI from using criminal evidence against athletes," Valverde said in a statement.
CONI accuses Valverde of violating article 2.2 of the World Anti-doping Agency's (WADA) code regarding the use of prohibited substances and has called for him to be banned for two years.
It says blood samples from Valverde taken during an Italian stage of last year's Tour de France matched DNA samples from suspect blood bags discovered in the 2006 Operation Puerto doping scandal.
Valverde has denied the allegations.
In February, the Madrid High Court declared CONI's procedure legally invalid since it said the committee, which is part of Italy's culture ministry, had no right to demand the seized blood samples from Spain.
It also ruled that the samples in the Puerto affair could not be used as evidence in another case and by another judicial body.
Valverde has long come under suspicion of doping after being implicated in the Puerto affair, although nothing came of Spanish investigations into his alleged involvement.
Valverde is a one-day specialist who is a two-time Pro Tour champion and has three times finished on the podium at the World Championships and was second in the 2006 Tour of Spain.