Three people have tested negative for bird flu after a "low severity" outbreak at a farm in Upham, Hampshire.
Officials revealed the results of the trio's tests today, as they prepared to slaughter 10,000 chickens to control the outbreak.
A 1km poultry restriction zone has been imposed, and the birds at the unnamed commercial chicken breeding farm are set to be culled, after evidence of the H7 bird flu strain was confirmed on Friday.
A Hampshire MP has said he is "very concerned" by news that bird flu had been detected at a farm in the Upham area.
George Hollingbery, who represents the Meon Valley constituency, said health experts had reassured him that the risk of danger to the public was "very low".
Animal health experts have revealed birds at a farm in Hampshire will be culled as a precautionary measure, as the low-severity strain identified can mutate to become more deadly.
A spokeswoman for the Animal and Plant Health Agency said a 1km cordon had been put in place around the farm to prevent the movement of poultry - though she declined to confirm where in Hampshire the farm was.
The restricted zone, which will be in force for 21 days, also bans the movement of eggs, mammals, and manure during that timeframe.
It is believed the strain is H7 - significantly less serious than the H5N8 strain found at a Yorkshire duck farm in November.
The spokeswoman told ITV News that this type of the virus did not spread as quickly or easily, and causes less severe illnesses in the birds themselves.
However, on rare occasions the H7 strain had been known to mutate into high-severity strains, she added, which is why a precautionary cull had been ordered.
Food safety experts have assured people that there is no risk to humans from bird flu.
It comes after a low-severity strain of the virus - H7 - was detected at a chicken breeding farm in Hampshire.
The government's Department for Environment, Food & Rural Affairs (Defra) have yet to name the farm involved.
A 1km cordon has been imposed around a Hampshire chicken farm after a low-severity strain of bird flu was found. The H7 strain is much less dangerous than the H5N8 strain detected in Yorkshire in November, and government experts say there is no link between the two cases.
The birds at the commercial chicken breeding farm will now be culled, and the country's chief vet has urged poultry keepers nearby to stay alert as the poultry movement restriction zone was put into force.
A "low severity" case of bird flu has been confirmed in chickens at a farm in Hampshire, the Department for Environment, Food and Rural Affairs (Defra) has revealed.
There has been an outbreak of bird flu on a British duck breeding farm according to The Department for Environment, Food & Rural Affairs (Defra).
Defra said it has confirmed at least one case of the virus at the farm in Yorkshire but they insisted the risk to public health is "very low", and said they have ruled out H5N1 but are embarking on a cull of all poultry at the affected farm.
A Defra spokeswoman said: "We have confirmed a case of avian flu on a duck breeding farm in Yorkshire - the public health risk is very low and there is no risk to the food chain.
"We are taking immediate and robust action which includes introducing a 10km restriction zone and culling all poultry on the farm to prevent any potential spread of infection. A detailed investigation is ongoing.
The latest case of bird flu in China, which appears to be related to a substrain of the H10N8 virus, is already displaying some worrying characteristics, an expert in infectious diseases has said.
Dr Jeremy Farrar, director of the Wellcome Trust, told BBC News:
A new and deadly form of bird flu has claimed its first confirmed human life.
The previously-unknown substrain of the H10N8 virus killed a woman who was admitted to hospital in China with fever and pneumonia, test results revealed.
The 73-year-old woman, from Nanchang City in Jiangxi province, died nine days after becoming ill despite antibiotic and antiviral treatment. She visited a live poultry market a few days prior to infection, suggesting an incubation time of around four days - similar to that of other bird flu strains.
The strain is believed to have spread from poultry and may pose a pandemic threat to the human population, experts said.
Reports suggest at least one other person is critically ill in hospital after being infected by the same strain in Jiangxi Province.