Europol, with cooperation from national police forces, has dismantled an organised crime ring operating across Europe, which was trading horsemeat unfit for human consumption.

66 people are understood to have been arrested as part of the operation, which was carried out in coordination with forces in Belgium, France, Italy, Portugal, Romania, Switzerland and the United Kingdom. Those arrested face charges including animal abuse, document forgery, perverting the course of justice, crimes against public health, money laundering and being part of a criminal organisation.

The investigation stemmed back to the horsemeat scandal, which erupted in 2013, after food testing revealed that processed meats on sale at supermarkets in the UK and Ireland contained significant quantities of unlabelled meat. The scandal quickly spread; processed red meat (mostly expensive beef) was found to be adulterated with less prestigious meats like pig and horse in foods on sale across Europe. An investigation by the Guardian uncovered evidence of undocumented workers being paid to process meat so old it had turned green, in testimony reminiscent of The Jungle, Upton Sinclair’s expose on the Chicago beef trusts from the turn of the last century, which led to the instatement of the Bureau of Chemistry, the precursor to the Food and Drug Administration.

The Europol investigation which led to the arrests reported over the weekend began in Spain in 2016, when authorities detected “unusual behaviour” in horsemeat markets. They found that horses from Portugal and northern Spain that were marked as "not suitable for consumption" were being slaughtered in two different slaughterhouses, their meat was processed in one facility and then sent to Belgium, one of the EU’s main exporters of horsemeat with their documentation and microchips doctored.

Over the course of the investigation, the Spanish Guardia Civil identified a Dutch businessman who was implicated in the original 2013 horsemeat scandal in Southern Spain. Police estimated that the Spanish operation was in fact a small part of a much wider European crime ring, which led to simultaneous investigations being carried out in other European states, and to Europol’s involvement in the case.

The unnamed Dutch suspect is thought to have controlled the operation from southern Spain, appointing his most trusted associates to direct operations in other European countries.

On Sunday, Europe said the swoop in Spain led to several bank accounts, properties and luxury cars being blocked and seized by police. 65 arrests were made in Spain, and the main suspect was apprehended in Belgium, according to the local press.