A MYSTIFYING 'crop circle' has appeared on a moor above Keighley.

The bizarre design was spotted close to Whetstone Gate, on the uplands between Riddlesden and Ilkley.

Aerial footage has been captured, using a drone, by Riddlesden man Stephen Auker.

Although baffled by how exactly it has been achieved, the 60-year-old believes the handiwork is down to humans rather than aliens.

"There don't seem to be any machine or tyre marks – but it's possible that if this has been there 'undiscovered' for some time they may have disappeared naturally beneath plant growth," said Mr Auker.

"What mystifies me is that the surface of some of the Ice Age stone has been removed – with no indication of tools being used – and a lot of very tough heather has been cropped down to less than three inches.

"I'm sceptical about the existence of aliens and believe this is down to man, but I just don't know how it has been done."

A friend and fellow metal detector enthusiast, Andrew Ward, alerted him to the strange shapes.

"He got in touch because he knew I had a drone and you can only really get a proper sense of it from above," said Mr Auker, who has posted his footage at youtu.be/iX15JS4E-po.