The RSPCA is warning people to be on their guard after reported sightings of a wolf in the countryside.
Police received several calls from locals who sighted a mystery large white dog on the loose in Cambridgeshire.
Residents in Ely, Soham and Littleport raised the alarm amid fears the animal could target children or smaller pets.
The animal is thought to be an escaped German Shepherd – Husky cross dog.
But the RSPCA warned anyone who sees it avoid it and call them directly.
A spokesman said: “The RSPCA advises people who think they have seen an animal like this to keep away from it and contact the police as soon as possible.”
One local who has seen the animal said: “It is very wolf like. I haven’t seen it but my friend has seen it and thought it was a wolf.
“Nobody seems to be able to catch it or knows where it has come from.”
Cambridgeshire County Council said: “We believe it is a Siberian Husky crossed with a German Shepherd, which we have been trying to catch over the last couple of days.
“Unfortunately the dog is quite nervous so runs away whenever it is approached.”
Cambridgeshire police said: “We received several calls last week regarding a white dog running loose in the area.
“We have passed details to the council who are trying to locate the animal and its owners.”
Richard Morley, from the Wolves and Humans foundation, said: “It can be very difficult to tell the difference between a wolf and a dog.
“You can generally only tell up close, and most wolf sightings are from a distance.”
Wild wolves have been extinct in Britain since the 1700s but there are still large populations in parts of Eastern Europe, Russia and Scandinavia.
Under the Dangerous Wild Animals Act 1976 any private keeper of a wolf – or first or second generation wolf hybrid – in Britain must have a licence from their local authority.