The deadly fish disease Spring Viraemia of Carp (SVC) has been discovered in imports of goldfish brought into the UK from a Hong Kong aquarium fish supplier.
Defra has confirmed that routine import checks have identified the virus in a consignment of goldfish imported from Tung Hoi Aquarium Company, Hong Kong.
Other fish from the same supplier have been purchased by fish dealers, potentially aiding the spread of the virus through the aquarium trade.
The Fish Health Inspectorate (FHI) and the Centre for Environment, Fisheries and Aquaculture Science (Cefas) have placed movement controls on all companies who purchased fish from the infected consignment and taken samples of fish for testing.
They have also advised other businesses which may have also imported fish from Tung Hoi Aquarium Co that there is a potential SVC risk from the fish.
Defra said that the authorities in the exporting country have been informed of the isolation of SVC and are conducting investigations to identify the source of the disease.
Imports of fish from the affected source have been prohibited pending the conclusions of investigations by Chinese authorities.
The disease, which is notifiable in the EU, is closely monitored by the Fish Health Inspectorate and there is a legal obligation to report suspected cases.
The virus causes clinical signs including darkening of the skin, swollen eyes, abdominal swelling, pale gills, trailing faeces and protrusion of the anus. Infected fish can also be lethargic and may show areas of bleeding around the skin and gills.
SVC affects common and ornamental Carp, Goldfish, Tench, Rudd, Pike and Wels catfish.
Anyone who observes deaths in affected species with similar symptoms to those above should immediately contact the Fish Health Inspectorate at Cefas's Weymouth Laboratory on 01305 206 673.
SVC is widespread in continental Europe, but is uncommon in the UK. Only 11 cases have been reported since 2001, with just a single case reported in 2007 and none in 2006.
The UK's largest outbreak took place in 1998, when the disease hit 40 sites across England and Wales.