BRUSSELS (AP) — Authorities have arrested at least 66 people in a European food scam which sold horse meat unfit for human consumption.

European Union police coordinating organization Europol announced Sunday that eight nations cooperated in the operation. In Spain, 65 people face a series of charges relating to public health, money laundering and animal abuse.

The operation took several months and the chief suspect, a Dutch businessman, was arrested in Belgium in April.

The case was linked to a 2013 scandal when Irish authorities detected beef burgers containing horse meat and a 2016 case in Spain, where old and other horses unfit for consumption were slaughtered for export.

Authorities in Belgium, France, Italy, Portugal, Romania, Switzerland, Britain and Spain cooperated in the operation.