The ‘clearest ever’ photo of a big cat prowling the British countryside has been uncovered, documentary makers claim.

The picture of the large panther-like creature was discovered in the files of a zoology organization.

It shows a large muscular black cat lying in long grass in Smallthorne, Staffordshire.

The photo was accompanied by a handwritten note dated March 17 - but it is unclear is which year it was taken.

The Argus:

Experts say if genuine it is ''probably the best photo of a British big cat that exists''.

The image is featured as one of several potential pieces of evidence supporting the existence of such cats in the British countryside.

They form part of a new award-winning documentary ‘Panthera Britannia Declassified’ released on Amazon Prime by Dragonfly Films.

The picture was unearthed by the assistant director of a center for zoology when he was working in their archives.

He said: “The photo is unambiguous, it is clearly a large cat of the Panthera genus, and it’s so clear we can even see its whiskers.

''The photo was attached to a mysterious handwritten letter, which includes a date without the year, isn’t signed with a full name, and doesn’t have the sender’s address.

''But it does state the photo was taken and if it’s genuine, then it’s the probably the best photo of a British big cat that exists.”

The films also has new DNA evidence proving the presence of at least one wild big cat near a sheep-kill in Gloucestershire in July 2022.

Tim Whittard, producer of ‘Panthera Britannia Declassified’, said: ''This astonishing lost photograph and amazing new scientific discovery form only a fraction of the collective evidence on display in the film.

“The documentary is predominantly data driven. We used real science and real experts, and tried to be as objective and analytical as possible.

''The research process for this show was intensive and exhaustive, and took us thousands of hours in various archives, libraries, museums, and laboratories, as well as in the field and meeting hundreds of eyewitnesses.

''The result is a mind-blowing voyage of discovery for viewers, which really takes this forward as serious zoological issue.

“The story is a sad one really - these majestic big cats could be legally owned without a license in the UK until 1976 and were very popular, being seen as fashionable status symbols at the time.

''When the laws surrounding exotic animal ownership changed a lot of people released their big cats into the countryside.

''So essentially, the animals people are seeing today are the offspring of abandoned pets for the most part.”

‘Panthera Britannia Declassified’ is available now to buy and rent on Amazon Prime.

It will also be broadcast on TV in the UK later this year as part of a special week of programming on Blaze (Freeview channel 64).