Groups working to protect the remaining pockets of red squirrels in England say they are “devastated” after an outbreak of a deadly disease was confirmed.

Volunteers with Cramlington and District Red Squirrel Group, in Northumberland, have spotted a number of ‘reds’ with symptoms of squirrel pox, and a carcass sent away for analysis has been confirmed as positive for the disease.

Squirrel pox is carried by grey squirrels, which are not affected by it, but causes red squirrels to die slowly and painfully.

The Department for Environment, Food and Rural Affairs (Defra) confirmed the single case, but says there is no threat to humans or livestock.