Police were last night investigating a sighting of a puma by two boys out walking their dog.

The creature was spotted by the teenagers just before midnight on Monday at Scar Top, Barnard Castle.

It is the latest in a string of glimpses of big cats in Britain's countryside.

Although the boys only saw the animal momentarily before it ran off into woodland, police said they described it as about the size of a big cat such as a puma.

There have been numerous reported sightings of pumas since the Dangerous Animals Act was introduced in 1976, which meant owners of big cats had to have a licence to keep them.

Many owners simply released their animals into the wild.

Some of the most conclusive sightings have been reported in the Barnard Castle area. Fur and a paw mark found near the carcass of a sheep near Whorlton, in Teesdale, several years ago, was found to belong to a puma.

Durham Police wildlife officer Sergeant Eddie Bell, who has investigated numerous sightings of big cats, said the animal spotted on Monday could well have been a puma.

Sgt Bell said: "I have no doubt that there are pumas living in the wild, and sightings reported around Barnard Castle have usually proven to be the most convincing.

"I will be looking a bit closer at this sighting."