Border agents at London’s Heathrow Airport recently arrested a slick customer in a major smuggling bust. The items he is accused of trying to sneak through customs? Some 600,000 eels.

According to the Evening Standard, agents at the airport caught a 64-year-old man from the Chessington area of London attempting to smuggle the eels into Hong Kong. Glass eels are considered a delicacy in many East Asian countries, but the European Union has enforced a total ban on their export since their numbers went into sharp decline.

The man had hidden the trays of eels beneath shipments of other, totally legal fish, but his simple scheme didn’t pass inspection. Officials with Britain’s Border Force consider the seizure to be a major bust, estimating that, on the eel black market, the seafood would have been worth nearly $1.5 million.

Having originated in Spain, the eels were returned to their home country. It is unclear if they would be eaten.