Among those being questioned are several vets.
According to the French newspaper Le Figaro, the enquiry began at the end of 2012 when an anonymous letter was sent to authorities making allegations about a horse-trader and owner of butcher shops in Narbonne in the south of France.
The investigation centres on horses used by the Sanofi Pasteur laboratory in Alba-la-Romaine in the Ardèche region of France.
Horses used by labs are usually sold to horse-traders afterwards with the stipulation that they must not find their way into the food chain.
Police suspect that horses used by this lab were at some point sold for human consumption.
“Is is not the same as the horsemeat affair last year,” Consumer Affairs Minister Benoît Hamon said on France’s RTL radio station. “This seems to be about horses which should have ended up in the slaughterhouse and might instead found their way into butcher shops as meat.”
Alain Bernal, a spokesperson for Sanofi Pasteur condemned the fraud, adding “we have co operated and will continue to co operate with the authorities on this ….It could involve several hundred horses if trafficking has been going on for several years.”
Sanofi Pasteur “uses horses in the fabrication of serums, medicines which save human lives, for example to protect humans from rabies, tetanus, snake venoms,” explained Alain Bernal.
He described the horse as “an antibody factory”. “You vaccinate it, it will generate antibodies in its blood. You extract the blood, you extract the antibodies, purify them and then that is made into a pharmaceutical product.”
Laboratories stipulate that such horses must not be used for human consumption and they are usually sold for leisure purposes or to veterinary schools.