An extremely rare coin that is no longer accepted in shops has sold for almost 8,000 times its face value.

The 25p coin found in one man's pocket looks like an ordinary 20p in terms of shape, but features a shield and a Sovereign's Orb with the word 'experimental coin'.

This is because the coin was only produced very briefly as a short-lived experiment.

It is thought to have been one of only 50 made by skilled craftsmen at the UK’s Royal Mint before the denomination was officially released into circulation in 1982.

Going under the hammer at RWB Auctions in Wiltshire, the 25p coin sold for a whopping £1,700 - which is £1,000 more than experts predicted.

The man who found the rare coins is not a coin collector and had just been given it in some change.

Unaware of its value, he left it in a drawer for several years.

The 25p coin worth hundreds is easy to mistake as a regular 20p.The 25p coin worth hundreds is easy to mistake for a regular 20p. (Image: RWB Auctions) Coin experts call experimental coins like this a ‘trial piece’ and at the time it was made, authorities had not yet decided if it would be worth 20p or 25p.

“We’re thrilled that this rare coin fetched such a high price," said Jon White, founder of RWB Auctions.

"It shows how vibrant the coin-collecting market is and how sought after such an experimental coin can be.

"Keep an eye on your change as a coin like this can easily be mistaken for a ‘normal’ 20p coin."