A 35-year-old Mars Bar has been found during a house clearance – and the discovery has gone viral amid claims it highlights the effect of "shrinkflation".

The chocolate bar with a best-before date of 1991 was found during a clear-out of a house in Scunthorpe.

Victoria Gordon, who runs the cleaning service, posted a photo on social media of the 62.5g bar alongside one of today's Mars Bars, which is 40g.

"It was nearly as big as my hand, which was kind of why I noticed it," she said.

Speaking on BBC Radio Lincolnshire, Gordon said: "We were clearing out a hoarder's house and everything we were rooting through was decades old.

"This Mars Bar stood out to me because as I picked it up it was nearly the whole length of my hand.

"I was like, 'Wow, look at the size of that!'"

A Mars spokesperson said: "Over the last 35 years, we have made a number of updates to our bar sizes and pack formats to reflect consumer demand, alongside considering wider external factors such as manufacturing costs and the price of cocoa."

Gordon, who runs Pocket Rockets, is not sure what she will do with the bar, but she said she might be sitting on a "gold mine".

"I do post some hoarding videos but I've never had anything go this viral," she said.

"It's so fascinating what people find so interesting. I almost put it in the skip [but] I might do a UK tour with it."