CITIZEN Chief Reporter Ben Falconer went on the hunt for evidence of big cats at a secret location in Gloucestershire with expert Frank Tunbridge:

I HAVE passed this secret big cat hot spot in the west of Gloucestershire several thousand times but a sighting has always eluded me.

Then again, I've never looked for one.

But the witnesses who have contacted tracker Frank Tunbridge weren't expecting to see a big cat slink through the undergrowth either.

That's why we are in a copse checking batteries and memory cards in Frank's trip cameras.

They are lashed to trees and posts along possible big cat thoroughfares, to try and catch its movements – and very existence – on video.

So far, the cameras sited across Gloucestershire have captured deer, dogs, wild boar, and even the odd reveller on the way home from the pub. And the cameras, like those used in BBC TV's Lost Land of the Tiger, may even have caught the moment a big cat wandered by.

"It's difficult to say categorically, but we have had a few where movement has been detected and then it whites out because they're too near," said Frank, who has seen what he believed to be a big cat four times in the British countryside. Several sightings around this spot prompted Frank to set up the cameras here but there are other ways of detecting its presence.

"I can smell where a cat has been before," says Frank, as he inhales a good noseful of the bark which may have been urinated on by the elusive mog.

Tracking

"If it's fresh, then you can pick it up – it smells like a domestic cat, iodine-like, but more powerful. They can also leave droppings around the tree."

Frank sometimes collects these, boils them down, and sieves them for evidence of what it's been eating. It's a good job he's got a strong stomach and a wife who presumably tolerates such behaviour. Trained in tracking by an ex-special forces member, he's alert to changes in the countryside most of us would never notice.

He points out footprints of dogs, deer, stoats and badgers while we are there. Sadly, no big cat prints however.

After servicing the cameras, Frank wipes a fetid-smelling dog meat roll over the tree, right in the middle of the camera shot. Its smell is pretty awful but it could be enough to tempt a big cat into the frame.

He's been fascinated by these creatures ever since his dad struck up a friendship with a Regent's Park Zoo keeper who sneaked young Frank in, free-of-charge, before opening time.

Then the Surrey puma captured his imagination in the 1960s and he's been on the trail of big cats ever since.

He fears big cats could be persecuted, mainly due to ill-informed public fear, if the DNA tests prove positive.

"These cats have been out there for many years," he said. "There has not been one attack in the UK. They are existing on an ample supply of wildlife including deer, and they are doing the environment a favour by keeping their population in check."