Details about how horsemeat masquerading as beef made it into the European meat markets are surfacing from court action.
French authorities estimate that between 2010 and 2013, 4,700 horses unfit for human consumption were slaughtered and introduced into the legal food chain.
Four hundred horse passports with anomalies were detected in France alone.
Due to falsification, suppression and/or modification of official health documentation by the group, the horsemeat, deemed unfit for human consumption, was able to fraudulently enter the European food chain. According to EU food chain legislation, all horsemeat is supposed to be traceable.
A man in Belgium is believed to be the head of the fraud.
An Investigating judge from the Tribunal de Première Instance of the Province of Luxembourg (Division Arlon), Belgium, began his inquiry in 2012.
France started its investigation in July, 2013, led by a judge from the Tribunal de Grande Instance of Marseille (Pôle Santé Publique).
A joint investigation team between France and Belgium was formed in May, 2014, with funding by Eurojust. This month the United Kingdom joined the team.
So far there have been 26 arrests, about $50,000 worth of cash has been seized and more than 200 horses will be examined by veterinary services.
Dozens of searches of commercial and private premises were carried out, more than 800 horse passports were seized plus medication, dozens of microchips and computer equipment.