A further 68,000 birds are being slaughtered on a sixth poultry farm in Suffolk in a bid to control the outbreak of bird flu in the region.
Another 68,000 birds are to be culled in Suffolk
Defra officials say the latest cull - more than double the other five combined - is precautionary and falls within the existing surveillance zone.
The move comes amid fears that workers at the farm have travelled to other farms that are deemed a flu risk.
More than 28,600 turkeys, ducks and geese have already been slaughtered.
Acting Chief Veterinary Officer Fred Landeg said the move is based on new information about exposure risk and stressed that all poultry keepers must immediately report any signs of the disease.
A spokeswoman at the Department for the Environment, Food and Rural Affairs (Defra) said the latest farm is owned by the same company that operates Redgrave Park Farm near Diss, on the Norfolk-Suffolk border, where the virus was first detected earlier this month.
The spokeswoman said employee routes between the farms are being monitored for signs of the disease spreading.
A 3km protection zone and 10km surveillance zone were immediately set up, and remain in place.
The sixth cull will include 56,000 ducks, 9,000 turkeys and 3,000 geese.
Bird flu has been confirmed at both the original site of the outbreak and one other nearby site owned by the same company.
The latest premises to be added to the cull list supplied poultry to the farm at the centre of the outbreak, but this latest move is more linked to employee movement, the spokeswoman said.
On Tuesday it was confirmed that turkeys culled at two other farms over fears they had been exposed to the disease tested negative.
These were Stone House, in West Harling, and Bridge Farm, in Pulham, both in Norfolk.
On Monday, tests showed birds at Hill Meadow Farm in Knettishall on the Norfolk/Suffolk border had been infected with H5N1, a strain of the virus at the centre of fears that it may mutate and cause an epidemic among humans.
Another of the farms, Grove Farm, Botesdale, Suffolk was upgraded to a slaughter site on suspicion of having the disease last week, after dozens of birds were found dead by officials.
But initial tests on 5,500 turkeys slaughtered found the premises were free of disease.
A variant of the deadly H5N1 strain is capable of being transmitted to humans.