The 20p 'mule' coin dating from 2008 fetched more than £60 at auction

The coin was minted without a date due to an error and quickly became a sought-after collector's items.

A rare 20p coin without a date on it has sold at auction for more than £60.

The coin was minted in 2008 due to an error and is now a sought-after collector’s item.

Prior to November 2008, the date on 20p coins would be found on the tail side.

However, the Royal Mint changed this so that the date would now be next to the Queen’s head.

But a mistake led to the old format being used on the Queen’s side and the new format being used on tails.

This meant that the first batch of British coins with no date on them were released into circulation for the first time in more than 300 years.

It is believed that around 250,000 20p coins minted in November 2008 entered circulation with no date on them.

The coin that was sold at auction attracted 14 bids and eventually sold for £61.09.

Here are some of the rarest Royal Mint coins in circulation the UK.

The rarest is the Kew’s Garden 50p, which was designed to mark the 250th anniversary of the gardens in 2009.

Only 210,000 coins were ever minted with this design.

The Kew Gardens 50p sells for £156.25 on average, but one seller received over £700 for one when they sold it on eBay.

The other rarest coins stem predominantly from the 2011 Olympics, with the wrestling, football and judo coins among the most valuable.

Only 1.1 million of each of these coins were produced.

Flopsy bunny and Peter Rabbit designs which were produced in 2018 are also highly valuable.

These coins - 1.4 million of which were minted - depict the characters from Beatrix Potter’s novels and celebrate the life of the English writer and these sell for around £5.

In 2019, 500 million coins were produced, with three new 50p designs.

These included one of Arthur Conan Doyle’s Sherlock Holmes, Paddington Bear at St Paul's Cathedral and the Tower of London.