Law enforcement authorities in Portugal, France and Spain seized shellfish and six tonnes of glass eels worth up to 10 million euros ($10.4 million) from the seafood market, Europol said on Thursday.
The delicacies can cost up to 25 euros per kilogramme (£2.2), but the poaching gangs exploited Asian workers by paying them as little as one euro per kilogramme of clams caught in polluted Portuguese waters.
The case was thus the first proven crime in the EUcombining environmental offences and trafficking for labour exploitation, Europol said in a statement.
The gangs mainly caught Japanese shellfish, particularly popular during the Christmas season on the Iberian Peninsula, and forged documents to pass them off as edible. This could have caused public alarm, as the constant consumption of contaminated shellfish puts people at risk of developing serious illnesses, including hepatitis.
Spanish companies were importing seafood from neighbouring Portugal and selling it without carrying out mandatory health checks to increase their profits, the Spanish Guardia Civil said in a statement.
The operation, coordinated by Europol, involved the Guardia Civil, French gendarmes and Portugal’s National Republican Guard.