A walker is adamant he spotted a big cat roaming the UK countryside, and says he has a picture to prove it.

The walker, in his 30s, is sure he caught a snap of the wild beast during a recent trip to Dartmoor.

Jon, who didn’t want to give his full name over online trolling fears, says he and his family were so unnerved by the sighting they quickly left the scene.

And on the way back to their car they stumbled upon a half-eaten deer carcass, he claims - adding to their fears.

Somerset County Gazette: Jon is adamant he spotted a big cat during his walk in DartmoorJon is adamant he spotted a big cat during his walk in Dartmoor (Image: SWNS)

Jon, from Devon, said: "Whatever it was, my concern was that I didn't want it to come towards us.

“When I first saw it, I stopped straight away and told my family 'Don’t panic and stay where you are. I think there's a big cat or dog up ahead’.

“It just felt a bit surreal and quite strange that my first thought was 'big cat'.

“I managed to get my phone out and got a picture just in my hand before it walked along a bit and ran into the woods - it had a huge tail, must have been a metre long with some white on the end.”

The family were walking to Fernworthy Reservoir on August 27 when they encountered the suspected big cat.

While walking on a main path near the forest, the man initially spotted what he believed to be a stray dog.

However, after watching the mystery animal move, he realised it more closely resembled a large cat.

After noticing the nearby family, he says the creature walked further up the path and over the brow of the hill, before stopping with just its head visible.

The family decided to turn around and walk to nearby Grey Wethers stone circle – but had to head back into the forest at a different point to get there.

And on the way the Jon claims they made a morbid discovery of an half-eaten deer carcass next to the path.

Then, while walking back to the car, the man claims they heard ‘roaring’ in the distance.

Jon said: “I'm quite a calm character so I thought I was seeing things and remained calm as I had my dog and child with me and didn't want to panic them.

“I was disillusioned - I thought I was seeing a massive dog but my brain knew it wasn't as it was so bulky at the back end, the rear legs and back end were as bulky as the front end and it looked very powerful and big.

“We decided to turn around as we had our one-year-old Labrador and our child with us.

“We decided to walk back into the forest maybe a quarter of a mile further up and straight away my son said ‘what's that?’.

"There was a half-eaten deer carcass just off the path in the woods and in the path there were quite a few bones about four to six inches long with broken bones from a rib cage.

“We then had to walk through thick woodland to get back to the car and while we were walking, we heard a roar – we thought we were going mad.”

Big cat 'sightings' have happened all over the UK - although conclusive proof of their existence has never been found.

Recent claims have been made about 'leopard DNA' being discovered in Gloucestershire.

However, a scientist said earlier this week the existence of big cats in the UK is unlikely due to the lack of sheep maulings.