Dog walker Barry Pearson stumbled across the beast which he claims was definitely 'feline'
This video was taken by a dog walker who claims it shows a big black cat "the size of an Alsatian" in a field.
Stunned Barry Pearson, 42, spotted the creature running across a field and slinking into woods last Monday near a railway line on the outskirts of East Lothian.
He was first alerted to the beast after noticing a herd of deer were being "spooked" across the field.
He said the cat - which was mostly black with white markings - was the size of a fully-grown Alsatian.
According to the Daily Record , the sighting last Monday near the railway line between Ormiston and Elphinstone in East Lothian, is the latest in a string of reports across the country over the years.
In 2001, there was a similar sighting in Ormiston, when Elaine Ainslie came "face-to-face" with a panther-like creature.
Mr Pearson, who runs an e-cigarette shop in Penicuik, had been walking his dogs Riley and Jules, a cross-breed and an Alsatian, on a "clear afternoon" when he spotted the creature.
He said: "I first thought it was a collie dog but when I took a closer look it was definitely feline. It was about the size between a Collie and an Alsatian.
"I was about half a football pitch away from it but if I had been a bit closer to it I might have been a bit frightened. It was very strange but very intriguing.
"I saw about six deer cut back across the field, then they cut back across. At that point the cat broke cover.
"I know it was from a distance, but when I saw it sitting in the field it was definitely bigger than a household cat.
"It definitely wasn't scared of us - I think it was eyeing us up.
"The deer obviously saw me and the dogs, and ran away from us first, and then it was the way they ran back, and turned. Then I saw the cat.
"It was off the beaten track, there were definitely no other dog walkers about."
He believes the deer, which had been initially startled by the movement of him and the two dogs walking along a fence by the field, were then prompted to run in the opposite direction by the feline predator lurking nearby.
Ormiston community councillor Cathy Jess said she had not been aware of any recent sightings.
She said: "There are plenty of animals roaming about if you catch them out the corner of your eye. But there are black Labradors, large dark coloured dogs -it could be anything."
The elusive "big cat" has been the source of much debate over the years, with sightings up and down the country.
While some are sceptical, it is believed that some of the creatures were let loose into the wild by their owners several decades ago.
It was legal and even fashionable in the 1960s and 1970s to keep exotic animals as pets in the UK, including leopards, pumas and panthers.
When the Dangerous Wild Animals Act was introduced in 1976, many owners gave their pets up to local zoos and wildlife parks, but a minority, worried their pets could be put down, set them free.
Between October 2009 and April 2012, police in the Lothians received seven sightings of big cats, with two in the Edinburgh area.
In the last five years, police forces across Scotland admit they have received reports of more than 140 big cat sightings.
A panther in the Edinburgh area and a large creature with a tail "similar to a lion's" were among the sightings in the Lothians.
In June 2011, police said "a large black car was reported which "was believed to be the size of a Labrador dog with a long tail".
And residents in Newhaven, Edinburgh, were convinced that a big cat was loose in January 2011 after spotting huge paw prints in the snow. They believed a puma or lynx had come in for food during the big freeze.
A police helicopter team also spotted a big cat on Arthur's Seat.
