Spanish police have arrested 29 people after seizing 180kg of critically endangered young European eels with a value on the hidden market of €270,000 (£237,000).
The Guardia Civil said the operation, in collaboration with Europol, had also led to 20 arrests elsewhere in Europe.
The elvers, or glass eels – prized as a delicacy in Spain and parts of east Asia – were found after officers carried out almost 3,000 checks and inspections in ports, airports and other transport hubs.
“Most of the offences relate to illegal fishing, unlawful possession, illegal trafficking of endangered species and violations of laws governing natural spaces,” the Guardia Civil said.
According to the force, eel smuggling has risen since Covid flight restrictions were eased.
“Criminal organisations have gone back to illegally exporting elvers that are camouflaged in hand luggage using special cases that contain bags injected with oxygen,” it said. “We’ve also tracked down shell companies specifically set up to ship elvers hidden in refrigerated food. We would remind people that the export of elvers is strictly prohibited.”
The Guardia Civil said eel smuggling had become a lucrative enterprise for highly organised gangs of international criminals who constantly update their routes and methods to evade the police.
“It’s become more and more common for them to choose different departure routes and to use airports in Serbia, Macedonia, and other eastern European countries, far from where the animals are fished,” it added.
A large proportion of the confiscated elvers have since been released into the Ebro Delta in north-east Spain.
In February 2020, a seafood salesman was found guilty of smuggling glass eels worth more than £53m out of the UK over a period of two years.
Gilbert Khoo, 66, transported the elvers from London to Hong Kong hidden beneath other fish between 2015 and 2017.
The European eel (Anguilla anguilla) is classed as critically endangered on the International Union for Conservation of Nature’s red list of threatened species.
“While there is demand for the species, pressures from trade – and unknown quantities in illegal trade – continue to be a serious conservation concern for the species,” the IUCN website says.
• This article was amended on 4 October 2022. An earlier version said that a seafood salesman was found guilty of smuggling 200kg of live eels which were worth £53m. In fact, he was arrested at Heathrow airport transporting 200kg of eels, but, the £53m figure related to the value of eels he had smuggled over a two-year period.