A couple believe they captured a panther on camera during a trip to the UK.
Footage of the elusive creature shows it prowling against the backdrop of a green field as the visitors spied something moving between the trees near to the Forest of Dean.
The anonymous couple were so intrigued by the unknown jet black animal - which the woman who captured it claimed was as tall as a fully-grown Labrador and twice as long - they sent it to be analysed by an expert.
The tourists were visiting family in the nearby area at the time when they filmed the animal in a rural area just off the A40, Gloucestershire Live reports.
Self-proclaimed UK big cat tracker Frank Tunbridge, who has spent more than three decades investigating their existence, was sent the clip and says it provides more evidence of the possibility of the creatures stalking Britain's countryside.
"To most people throughout the UK the concept of large predatory wild cats, similar in description to black leopards and pumas living a feral existence in our woods and other wild places is unbelievable," said Mr Tunbridge, 74.
The enthusiast believes there are around 16-24 sightings of big cats every week in the British countryside, although many go unreported for fear of not being believed.
Mr Tunbridge, from Podsmead, Gloucestershire, added that "the mere thought of coming across a big cat" whilst on a quiet stroll was enough to "fill most people with dread".
"The incredible facts are though, that this happens on a weekly basis throughout the UK.
"I defy anyone to take a photo on their camera phone when faced with this situation.
"Most are literally frozen to the spot with fear, and will not take your eyes off of the creature, and then after five to 10 seconds later it will be gone in a couple of bounds, generally disappearing into some nearby cover, but leaving you with an image that stays with you forever."
The Cotswolds and Forest of Dean areas have seen numerous reported sightings of creatures believed to be big cats over the years, with another man claiming he saw a lynx in the beauty spot in January last year.
"The whole tantalising subject of 'The British Big Cat' has been rolling on for decades now, without a satisfying conclusion," Mr Tunbridge continued.
"The evidence is now overwhelming with thousands of eye witness reports."
Mr Tunbridge believes that Brits who once owned exotic animals were forced to release them into the wild when the Government brought in tougher laws on keeping them during the 1970s.
However, scientific evidence has been carried out over the years on animal carcasses thought to have been proof of big cats nearby, providing conflicting DNA results.
The big cat hunter claims that, after five decades, there may be leopards and pumas "still roaming around", as well as a naturalised breed of which would be "generally black or fawn in colour, with a long body and tail".
