The inquiry will be carried out by police officers from the Centre for the Prevention of Damage to the Environment and Public Health (OCLAESP), prosecutors added.

The probe was launched last July after the organisation responsible for the disposal of medical waste produced by the Tour de France teams discovered "suspicious medical equipment," a judicial source said.

According to French daily Le Monde, the investigation involves a number of teams including Astana, home of 2009 Tour de France champion Alberto Contador of Spain and seven-time American winner Lance Armstrong.

Sports daily L'Equipe backed up Le Monde's claims regarding Astana, and added that some of the syringes being analysed had been used by the Kazakh team.

"These syringes, used by the team of race winner Alberto Contador, were sent to the Parisian forensics laboratory Toxlab of Professor Gilbert Pepin and are currently being analysed to determine their contents," read an article on the L'Equipe website.

AFP/Expatica