Europol has announced a 50% increase in arrests over European eel trafficking, seizing 15 million of the endangered species.
The illicit trade in exporting the eel from Europe to Asia is said to be worth £2.6bn (3 billion euros) each year.
Enforcers have arrested 153 people across the EU in connection with eel trafficking in the 2018-19 period, a 50% rise in arrests. Some 98 people were arrested in 2017-18 and 48 people in 2016-17.
Although an export ban has been in place since 2010, between 300 and 350 million baby eels – known as glass eels – are trafficked every year, according to Europol.
Jeopardising the recovery of the endangered species, the illicit trade is said to be as lucrative as drug smuggling.
European eels are brought to Asia through either being disguised within other fish in air freight containers, incorrectly declared as other unprotected eel species or hidden in suitcases on long-haul flights.
The glass eels are then farmed to be served as a delicacy.
Jose Antonio Alfaro Moreno, from Europol, said: “This is our flagship operation in terms of environmental crime.
“All the arrests mentioned are in Europe with the majority from Spain, France and Portugal.
“However, there are also five ongoing criminal cases in the USA carried out by the US Fish and Wildlife Service involving the illegal import of eel meat coming from Asia containing DNA of the European eel.”
The UK Wildlife Crime unit, which acts as a support unit for police, says investigations are ongoing after seizures were made in the UK and proceedings from another case are due in court next year.
Ian Guildford, investigative support officer, told the Sustainable Eel Group’s 10-year anniversary event that cooperation was needed as one single agency could not solve the problem.
The Sustainable Eel Group (SEG), an international organisation seeking the conservation and management of the endangered species, has developed a code of conduct for the commercial sector to play a role in restoring fish stocks.
Andrew Kerr, chairman of SEG, said: “Trafficking of the European eel is the world’s great wildlife crime in both traded individuals and market value.
“It affects 25% of the total stock of European eel and is hampering the recovery of this precious species.
“It is therefore vital that we stop all smuggling because it undermines every single effort used to establish adequate protection from other human impacts.”
BBC Countryfile recently exposed dealers looking to illegally export the species.
Posing as a fisherman, presenter Joe Crowley was approached by Chinese and Russian buyers who were prepared to pay seven times the normal catch price for the eels to be sent out of the EU.