British government experts confirmed on Saturday that the H5N1 bird flu virus outbreak at a Suffolk turkey farm was the Asian strain.
The Department for the Environment, Food and Rural Affairs said the virus strain that killed 2,600 turkeys at a Bernard Matthews farm was identified as the "highly pathogenic" Asian strain, similar to a virus that was found in Hungary in January.
It was the first time the deadly H5N1 strain was found on a British farm.
British Deputy Chief Veterinary Officer Fred Landeg said all 159,000 other turkeys on the farm would be slaughtered as a precaution to contain the outbreak. He urged poultry farmers to step up their bio security procedures.
A three-kilometer protection zone and 10-kilometer surveillance zone has been set up around the farm, while strict movement controls have been in place and farmers been told to keep poultry indoors.
In May last year, more than 50,000 chickens were culled after an outbreak of the H7 bird flu in farms in the neighboring county of Norfolk.
In March 2006, a wild swan found dead in Scotland had the H5N1 strain of the virus.
The H5N1 strain can be transmitted to humans and has killed more than 160 people worldwide since 2003, most of them in Asia.