Officials in Britain have confirmed that the bird flu strain detected in turkeys on a farm in Norfolk is the deadly H5N1 strain of the virus.
The farm near Diss in Norfolk which breeds turkeys, geese and ducks have seen all their poultry culled as a precautionary measure and a 3km protection zone and a 10km surveillance zone set up around the facility.
All poultry within those zones must be isolated from wild birds.
The birds, in total 6,500, were free range and had outdoor access and may have been at greater risk of catching the disease because of wild bird migration.
The farm is co-operating with officials in efforts to contain the outbreak.
All workers on the farm who may have been exposed to infection have been given Tamiflu and anyone working on the infected premises dealing with the outbreak will also be given Tamiflu prior to commencing work.
This latest outbreak of the lethal H5N1 bird flu virus is the second to occur in England this year and there are suspicions the outbreak is closely related to outbreaks in the Czech Republic and Germany, which are also suggestive of a possible wild bird source.
Veterinary officials say further tests may indicate the origin of the strain and a thorough epidemiological investigation tracing any dangerous contacts is already underway.
Animal Health officials are keeping all registered poultry keepers informed of the developing situation and are warning them to be extremely vigilant, report any suspicions of disease immediately and practice the highest levels of biosecurity.
Experts say swift reporting of disease and stringent biosecurity are mandatory in controlling the spread of the virus.
An outbreak of H5N1 avian influenza in Suffolk in February at a Bernard Matthews poultry farm in Lowestoft was contained and the facility received reimbursement of £589,356 for healthy birds compulsorily killed to prevent the disease spreading.