A 6ft boa constrictor has been spotted at a beauty spot in North Yorkshire, prompting warnings to dog walkers and other members of the public.

Ed Ryder spotted the reptile while walking with his girlfriend at Swinsty Reservoir, near Harrogate.

Mr Ryder took this picture of the tail-end of the snake before it moved away.

Yorkshire Water, which owns the site, has warned people to be on their guard even though experts believe it is unlikely the animal poses a danger to people.

Mr Ryder said: “I’m not fond of snakes at all, I didn’t even like my Grandma’s snake draught excluder. I enjoy running around Swinsty and I have been wondering how to get my speed up - I don’t have to worry now.”

He said he spotted the snake at about 6pm on Saturday. It is believed to be an abandoned pet.

Mr Ryder, who runs Biskit Marketing, in Otley, thought it was a very big adder, but experts from the Yorkshire Naturalists Union confirmed it was a boa constrictor, measuring about 6ft (1.8m).

Geoff Lomas, site manager for Yorkshire Water, said: “Over the years, we’ve discovered a number of escaped or unwanted exotic pets at our recreational sites across the region, such as terrapins and koi carp, but never an exotic snake.”