A "very small" pet poultry flock will be culled following a bird flu outbreak at a residential property on the Holkham estate.
Defra confirmed on Sunday night that avian influenza had been identified at a premises near Wells.
The disease, carried by migrating birds, is a major threat to East Anglia's poultry industry at this time of year, and prompted culls of thousands of turkeys and ducks last winter.
But the latest case was found in a domestic home which only kept a small backyard flock of pet birds, including turkeys and chickens.
A spokesman for the Holkham estate said: "A case of bird flu has been identified at a single residential address at Holkham, with a very small flock of housed fowl.
"A 3km control zone is now in place and the situation is being monitored carefully."
Defra said further testing is under way to confirm the pathogenicity of the virus strain, and "all birds on the infected premises will be humanely culled."
A spokesman added: "A number of birds have already died on the premises, all remaining birds will be humanely culled to limit the risk of onward transmission."
The case at Holkham is the latest in a series of outbreaks in domestic and commercial premises across the country.
It comes after a national bird flu prevention zone was declared earlier this month in order to prevent the spread of the disease which ravaged East Anglia's poultry industry last winter.
It has now become a legal requirement for all bird keepers - whether large commercial farms or back-yard hobbyists - to follow strict biosecurity measures to help protect their flocks.
UK food and health agencies advise that the risk to public health from the virus is very low and that avian influenzas pose a very low food safety risk for consumers. Properly cooked poultry and poultry products, including eggs, are safe to eat.
Bird flu is a notifiable animal disease. Poultry keepers and members of the public should report dead wild birds to Defra’s helpline on 03459 33 55 77 (option 7) and keepers should report suspicion of disease to APHA on 03000 200 301.
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