Spanish law enforcement says it has stopped a gang smuggling glass eels to Asia for lucrative profits.

Four Chinese citizens, three Spaniards and three Moroccans were arrested in Spain in an operation coordinated by the European Union's police body, Europol, and involving Spanish and Portuguese investigators, The Associated Press reported.

Smuggling eels is a burgeoning illicit traffic that is worrying both law enforcement agencies and scientists.

Police say 460 kilograms (1,014 pounds) of glass eels were seized in southern Spain with a market value over 400 million euros ($490 million). The ring exported the baby eels bought in Spain through Portugal and Morocco, either concealed in suitcases or in cargo containers sent to Hong Kong, Mainland China and South Korea.

Police also seized 364 suitcases possibly used to smuggle the eels.

• Oregon Hagfish Slime Coats Cars After Truck of Eels Overturns
• Electric Eels 'Supercharge' Their Shocks by Curling Up: Study