BRUSSELS (Reuters) - Europol said on Sunday 66 people had been arrested for trading horsemeat unfit for human consumption and it had seized bank accounts, properties and luxury cars following an investigation into a food scandal that shocked European consumers.

Tests carried out in Ireland in 2013 showed that meat in some products labeled as beef was in fact up to 100 percent horsemeat.

Spanish police began investigating a group which slaughtered Spanish and Portuguese horses too old or in too bad a condition for human consumption, forged their documentation and sent them to Belgium, a large horse meat exporter in the European Union.

The European police agency Europol said 65 people were arrested in Spain, and the main suspect, a Dutch citizen, was arrested in Belgium.

“In Spain, 65 people were arrested and charged with crimes such as animal abuse, document forgery, perverting the course of justice, crimes against public health, money laundering and being part of a criminal organization,” it said in a statement.

An EU investigation revealed that less than 5 percent of all beef products tested had come back positive for horse DNA.