£1 coins with errors can sell for large sums of money online.
The new 12-sided one pound coin came with a number of errors and the new currency was tested.
This included running metal dyes, incorrect designs and silver centres that fell out.
However, another rare £1 coin with a minting error has reportedly been found with an entirely new design flaw.
The new £1 design appeared to have been stamped on an old £1 base.
This means the coin, usually two colours, is just the original gold colour, and the 12 sides are not as defined.
One coin has sold on eBay on January 24, 2017, for £205.
Change Checker has also reported the finding of one of the mysterious coins.
Auctioneers named Timeline in London are also selling one of the coins on the 21 February.
What should you do if you find one of the coins?
The Royal Mint Museum offers free verification for those who believe to have found rare coins.
Another rare coin has sold for a large amount online recently.
A £2 coin has sold online for £102.50, thanks to a rare minting error.
The coin was created to celebrate the 200 year anniversary of the slave trade.
Sold on 15 January this year, the popular coin had nine bids made on it by three bidders, which quickly escalated from £1.99 to the rather large sum.
But how can you spot one of these coins?
