Viking squirrels may have brought a plague of leprosy to Britain, according to a new study.
Researchers believe the deadly and disfiguring disease, which was endemic in England for centuries, could have been carried across the North Sea in the fur of the animals.
Vikings kept red squirrels as pets and traded their pelts.
Cambridge University archaeologists came to the conclusion after studying the skull of Medieval woman unearthed at the end of the 20th century in Hoxne, Suffolk.
Analysis found the woman, thought to have lived between 885AD and 1015AD, had been infected with the same strain of leprosy found in skeletal remains in Denmark and Sweden.
Medieval England had strong trade links with Scandinavia, with Kings Lynn and Yarmouth significant fur ports.
"It is possible that this strain of leprosy was proliferated in the south-east of England by contact with highly prized squirrel pelt and meat which was traded by the Vikings at the time this woman was alive," said Sarah Inskip, research associate at St John's College, Cambridge.
She added: "Research has already established that leprosy can be passed from armadillos to humans, so that it may also come from squirrels is an interesting idea. It is questionable how long the bacteria could have survived on fur or meat, but it's notable that squirrels were also sometimes kept as pets."
The 'Woman from Hoxne' was also found to have been infected with the same strain as leprosy as a man in Great Chesterford, East Anglia, who lived as early as 415AD to 545D, suggesting the disease persisted for hundreds of years in the south-east.
Ms Inskip said: "This new evidence coupled with the prevalence of leper hospitals in East Anglia from the 11th century onwards adds weight to the idea that the disease was endemic in this region earlier than in other parts of the country.
"Perhaps it's the movement of people and prolonged connection between East Anglia and Scandinavia that's important to our understanding of the history of leprosy in the UK, but further research refuting or confirming the role of the fur trade could be highly enlightening and exciting."
The last human case of human leprosy in the British Isles was over 200 years ago, but last year red squirrels with the disease were found on Brownsea Island in Dorset.
The disease affects squirrels in a similar way to humans - resulting in lesions on their muzzles, ears and paws.
