'One of the rarest modern coins' sells for £4,500

Coin expert Christopher Collects says there could be more of its kind

"One of the rarest modern coins" that was produced with the wrong date has sold for £4,500.

The 50p date that was printed on the heads side - 1990 - does not match the design on the tails side, which was supposed to be used on 1989-dated coins.

A private seller found the coin and asked the Britannia Coin Company (BCC), based in Royal Wootton Bassett in Wiltshire, to sell it on their behalf.

Christopher Collects, a coin expert who works for BCC, said there "could definitely be more" as "nobody has been looking for the mistake before".

The Gibraltar coin shows a portrait of Queen Elizabeth II on the heads side along with the date 1990 when it should have been 1989.

It is because the chorister design on the tails side - which shows a Christmas-themed choir boy and a puppy - is usually seen on 1989-dated coins.

Mr Collects hailed it as "one of the rarest modern coins out there".

The coin should have read "1989" rather than "1990"

The chorister design on the tails side s usually seen on 1989-dated coins.

The £4,500 sale price makes this 50p more valuable than the 2009 Kew Gardens 50p.

Examples of this well-known rare coin can sell online today for around £250.

'Worried it was fake'

Mr Collects said: “I was worried this coin was a fake, so I got a second opinion from the experts at the Numismatic Guaranty Company

"They are specialists in rare coins and authenticated the Gibraltar 50p as a real mint error."

Other examples of mint error coins where a problem occurred in the manufacturing process are undated 20ps.

In 2008, The Royal Mint released around 250,000 20ps into circulation without a date on the coin.

These error coins can sell for more than £100.