Three Malaysian residents were caught by Dutch border police on Thursday for attempting to smuggle hundreds of thousands of baby eels through Amsterdam’s Schiphol airport.

Officials got suspicious when the two men and a lady attempted to get through airport security with eight luggage bound for Malaysia through Portugal on Monday.

“Inside the cases were bags with water and baby eels,” said the NVWA Dutch food and goods watchdog.

“NVWA inspectors discovered 105 kilograms (231 pounds) of glass eels. That’s around 300,000 eels,’ the body said in a statement.

“The eels are to be released back into Dutch waters.”

Over the last four decades, critically endangered European eel populations have been devastated, falling by as much as 99 percent in some areas, according to EU figures.

Glass eels, or young transparent eels, are highly sought in Asia, where they can be fattened in farms and cost even more than caviar in the mid-2000s.