Cases of bovine TB have been found in pigs in Cornwall, the BBC has learned.
TB is not a notifiable disease in pigs, state vets said
Two pigs and some piglets from a farm near Bodmin were sent for slaughter, but tests showed they had the disease, the owner of the Cornish abattoir said.
The State Veterinary Service said it had no record of when it was last informed of a case of bovine TB, as it is not a notifiable disease in pigs.
The Department for the Environment, Farming and Rural Affairs (Defra) said it was monitoring the farm.
Farmer Martin Appleton said: "They went in three batches as I remember.
The first had infected heads the next batch all had infected heads and the last one was infected with the carcass which was infected as well."
Mr Appleton said he thought he knew the cause of the problem."
"Badger proofing is nearly impossible.
"We've got open sheds either side. You can not keep it in - it will climb or tunnel. A hungry badger will go where it wants."
Many farmers have campaigned for badger culling but Pauline Kidner from Secret World Wildlife Rescue disagrees.
She said: "The disease can be latent in those animals and can then come to the surface through stress and that how the disease can go out into the wider circles.
"Culling of an animal alone is not going to resolve the problem."
Abattoir owner Vernon Lobb said he had been in the meat business all his life and it was the first case he had heard of.
"Bovine TB, as far as I'm concerned, I've never experienced it in a pig."
At the moment, about 600 Cornish cow herds are affected by the disease and farming leaders say they hope this is an isolated case for pigs.
BBC South West Environment Correspondent Adrian Campbell said: "There's no risk to human health from TB in pigs and there's only a limited risk of it spreading from this isolated farm.
"But this discovery is unusual and unwelcome."