'Gardeners' World' star Monty Don's golden retriever has died.

Monty's dog Nigel (c) Instagram

Monty's dog Nigel (c) Instagram

The 64-year-old gardening expert - who is best-known for presenting the BBC TV series - has announced via Instagram that Nigel passed away after he was "suddenly taken ill".

Alongside a picture of his dog, Monty wrote on the photo-sharing platform: "I am very sorry to announce that Nigel has died.

"To the end he was happy, healthy and his usual calm, lovely self. But he was suddenly taken ill and he slipped quietly away with no pain or suffering and is now buried in the garden with lots of tennis balls.

"Rest now old friend. See you in the sweet bye and bye. (sic)"

Monty subsequently posted a series of throwback photographs of Nigel and thanked his followers for their kind messages.

He wrote: "Thank you for all your lovely and kind messages about Nigel. They are overwhelming. I have posted more pictures of him on my website montydon.com (sic)"

Monty previously discussed his love of dogs in an interview in 2016.

The TV presenter observed that dogs are able to build relationships with humans in a way that other animals simply cannot.

He explained: "I like dogs because they are not humans.

"I get very uncomfortable when people start talking about dogs as 'my boys'. What is wonderful is that this is a wild animal which has chosen to go into partnership with you. It is the only wild animal that really does that."