The pigs are being tested for disease in a control zone.
There was suspicion of swine vesicular disease in pigs at a site near Downham Market, Norfolk, which led to a 10 km zone being put in place.
TheDefra said "tests fully rule out" foot and mouth disease.
Other possible causes were being investigated.
The department said that the restrictions on pigs in the area would stay in place until further testing was completed.
Following reports of a possible case of foot and mouth disease on a farm in Norfolk, we put in place restrictions on the premises and took samples for testing.
The presence of this disease has been ruled out by testing. Other possible causes are still being investigated.
The zone was introduced as a precautionary to prevent the spread of disease.
neighbours would be updated of any developments
There are signs of foot and mouth disease in pigs.
There are blisters at the top of the hooves.
The signs of swine vesicular disease can be confused with foot and mouth disease, so it's important to report any suspicions.
The National Farmers Union is aware of the investigation, according to a spokesman.
The full test results will confirm the nature of the case.
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