Dutch border police have arrested three Malaysian citizens for attempting to smuggle hundreds of thousands of baby eels through Amsterdam's Schiphol airport, authorities said Thursday.

The two men and a woman were detained on Monday after officials became suspicious when they tried to take eight suitcases through airport security, heading for Malaysia via Portugal.

"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% in some areas, according to EU figures.

Young transparent eels, known as "glass eels," are particularly prized in Asia, where they may be fattened on farms, exceeding the price of caviar in the mid-2000s.