North Yorkshire Police said: “We are appealing for information after two dogs sadly died after eating something that is believed to be toxic on a walk at Lindley Wood Reservoir between 31 March and 15 April.

"We were made aware of what happened at around 4pm on Tuesday 16 April. We’re carrying out enquiries to find out more about what happened.

"If you have any information that can help us with our investigation, please get in touch.

"We would also like to hear from any other dog owners who believe their dog may have been affected in similar circumstances after visiting the location in recent weeks.

"You can email [email protected]. Or you can call us on 101 quoting job number 12240069458.”

Lindley Wood is one of a number of reservoirs in the Washburn Valley, near Harrogate, which are popular with visitors.

One of the dogs’ owners has issued a tribute to his pet. James Bevan, the director of a digital marketing agency from Leeds, confirmed his five-year-old Winston had died from kidney failure after being seriously ill for eight days.

Mr Bevan said: “We said the hardest farewell to our boy after he had been fighting acute kidney failure from toxic poisoning for eight days. My heart is in pieces. I feel angry, sad and robbed all at the same time. Five years old is far too young to lose him.

"Winston ate some poison/something toxic on Sunday 7 April at Lindley Wood Reservoir. This happened to another dog two weeks ago there who also sadly lost their life. I’ve spoken to the owner and our stories align.

"Please do not walk in Lindley Wood at the moment with your dog. Tell people who do about this as it can’t be a coincidence and I wouldn’t wish this on anyone.

"I don’t have the words to do this justice right now. Maybe I never will. Everyone knows what he meant to us. My boy. My best friend. My team mate. My world. He changed our lives completely and made everyone who met him love him. I’m so sorry I couldn’t save you buddy...we tried everything we could but it just wasn’t enough”

The other dog which died was a cockerpoo called Bear, owned by Manni Peacock, from Bingley, who runs a dog walking business. They visited Lindley on March 31.

Yorkshire Water, the landowners of the reservoir, have also been informed.

Lindley Wood Reservoir: Two dogs die after eating 'toxic' substance at popular Yorkshire dog walking spot