The H5N8 strain – which can be transmitted to humans – was identified in a small flock of chickens on Amos Hill Farm last Friday.

A 3km protection zone and a wider 10km surveillance zone, within which neighbouring farms and wildlife are tested, have been put in place around the infected premises to limit the spread of the disease.

Defra said the flock contained about 35 birds, of which a number had died naturally and the rest had been culled. A full investigation is under way to determine the source of the infection.

In addition, Defra has defined an area between Henshaw and Newbrough as being at ‘higher risk’ of contracting avian flu.

Defra declared a nationwide prevention zone on December 6, legally requiring captive-bird and poultry owners to keep their birds indoors, in a bid to prevent an avian flu outbreak on mainland Europe reaching Britain.

H5N8 has since been identified on three poultry farms in Lincolnshire, one in Suffolk, on a commercial game farm in Lancashire and in backyard flocks in North Yorkshire and Carmarthenshire.

This week, free-range egg producers fell foul of the ‘keep ‘em inside’ order, because their hens will have been indoors for longer than the 12 weeks allowed under EU regulations.

Their eggs have now been downgraded to ‘barn produced’, with stickers being put on egg boxes to explain the situation to customers.

Chief Veterinary Officer Nigel Gibbens said: “Besides poultry to poultry infection, bird flu is also transmitted via the environment, for example in wild bird droppings, and it is vital that keepers practice strict biosecurity.

“This means taking precautions, such as putting up netting, keeping food and water inside and disinfecting footwear and equipment after contact with birds.”

Anyone out walking who notices dead water fowl should report it immediately to either Defra or a local vet.

helen.compson@hexham-courant.co.uk