Bird flu has been found at a poultry farm outside Diss - the third case confirmed near the town this month as the disease's worst-ever epidemic continues.

A highly pathogenic strain of avian influenza was confirmed in commercial premises near Shelfanger on December 20.

Defra says all poultry on the infected farm has been humanely culled, while a 3km protection zone and a 10km surveillance zone have been enforced around the site.

It comes after two other bird flu cases were confirmed in commercial poultry near Redgrave, on December 8 and 11.

The recent cases illustrate the continuing threat from the disease - although the pace of the outbreak has slowed since its peak in autumn.

Norfolk recorded more than 40 cases in October alone, sparking the culls of hundreds of thousands of chickens, turkeys, geese and ducks as East Anglia became the national epicentre of the epidemic.

But although the region's case numbers are now much lower, farmers and backyard poultry keepers have been warned to maintain strict biosecurity during the high-risk winter season, when the return of migrating birds brings the potential for more outbreaks.

Chief vets have enforced a mandatory housing order to bring all birds indoors, and the government offered a support package in October which includes allowing farmers to be paid compensation from the outset of planned culling rather than at the end, to "help stem cash flow pressures".

But calls have been made for faster and retrospective compensation or the culling of flocks, an urgent review of shutdown periods for affected farms, and an extension of a derogation which allowed for turkeys, ducks and geese to be slaughtered early and frozen so they could then be defrosted and sold to customers between November 28 and December 31.

Zoe Leach, East Anglia regional director for the National Farmers' Union, said: "Recent cases are a reminder that avian influenza remains a threat to all bird keepers.

"Although the frequency of new cases has slowed, we’re continuing to experience the worst outbreak of the disease in the UK to date, with no end in sight.

"The financial implications of avian influenza are huge, and the emotional strain on affected farmers, their families and staff members is devastating, with many now forced to reconsider their future.

"We continue to urge everyone to remain vigilant. Maintaining good biosecurity measures is vital for all bird keepers, whether you are a commercial farmer or someone who keeps a small number of birds."