Remy di Gregorio is facing charges of being in possession of unauthorised medical equipment following his arrest this week, a French magistrate said Thursday.
We're talking about medical or paramedical practices which are prohibited. We might not be dealing with a doping substance, but the method is prohibited
A Marseille-based doctor who was also arrested has since admitted mixing blood from Di Gregorio with ozone and reinjecting it in a bid to improve the cyclist's performance.
The doctor, 75, has been charged with "using banned substances or procedures on an athlete" and "the illegal practice of medicine" and remains in custody with Di Gregorio.
The equipment found in Di Gregorio's possession was a glucose injection kit, which requires prior medical justification during competition, Marseille magistrate Jacques Dallest said.
Di Gregorio, who has been suspended by his Cofidis team following his arrest Tuesday and has dropped out of the Tour de France, admits receiving injections, but denies any charges of doping.
The 26-year-old French cyclist was arrested following a police raid at his team's hotel in Bourg-en-Bresse outside Macon in eastern France on Tuesday as part of an investigation into the organised trafficking of doping substances.
He was taken to Marseille for further questioning by investigating magistrate Annaick Le Goff, along with two other men, who were suspected of "having dealings" with Di Gregorio.
One of the two other men was released on Wednesday. He had been in possession of vitamins, nutritional supplements, blood transfusion kits and other products which are still being analysed.
"This individual was a friend who had come from Marseille to drop off the products, bought by the rider over the internet," said Dallest.
He added that none of the products had been supplied by the doctor.
Le Goff said although other people had been implicated in the affair along with Di Gregorio, "it's not the case that a whole team is being implicated".
Cofidis, who had suffered doping scandals because of unscrupulous riders in the past, pledged to sack Di Gregorio if charges of doping or attempted doping are confirmed.
"If the suspicions are confirmed, he will be sacked immediately in accordance with the stipulations in his contract and in line with the ethical policy of the team," a Cofidis team statement said.
According to Dallest, the doctor helping Di Gregorio admitted to police he had injected blood taken from Di Greogrio back into him after treating it with ozone.
Ozone is used for purification purposes at both medical and industrial level but its therapeutic, or performance-enhancing uses remain a subject of debate.
But for the magistrate, it amounts to prohibited doping methods.
"We're talking about medical or paramedical practices which are prohibited. We might not be dealing with a doping substance, but the method is prohibited, said Dallest.
At least four injections were carried out on Di Gregorio between the end of May and the end of June, Dallest said.
He added that the doctor, who has an office in Marseille, led a "luxury lifestyle" and that 26,000 euros in cash had been found at his home after it was raided by police.