A shipment of sub-adult arowana has been seized during a raid at a property in east London.
According to a report from the BBC, officers found 11 arowana, which it says are worth up to 2000 each.
The raid followed a tip-off to police about a shipment of the fish that had arrived in the UK from Singapore, one of the world's largest producers of arowana for the aquarium hobby.
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The fish, which are said to be around 45cm/18" in length, have been seized and one man has been arrested.
The report says the raid was organised by the Metropolitan Police's Wildlife Crime Unit, as part of Operation Charm, which is targeting the trade in endangered species.
Arowana are protected by the Convention on International Trade in Endangered Species (CITES) and all fish must contain a microchip confirming their identity as captive bred fish.