A distinctive 50p piece from the Royal Mint has changed hands for over four hundred times its nominal value at auction, with experts estimating that thousands remain out in the wild.

The collectible Blue Peter 50p coin, struck to commemorate the London 2012 Olympic Games, recently realised £220 on an online marketplace after drawing ten separate offers. A separate specimen has previously commanded as much as £286.

The design was created by Florence Jackson, who won a Blue Peter-sponsored competition to have her artwork minted. The coin displays an athlete competing in the high jump event and entered circulation in 2009 prior to the Olympic Games.

While roughly 20,000 of these coins were produced, they were never formally issued through normal banking channels. Nevertheless, those who collect such items believe numerous examples have since entered regular monetary circulation, meaning some may still be hidden among everyday change throughout Britain.

The coins were initially sold to the public for £1.09, but their scarcity combined with their Olympic link has considerably increased their appeal to collectors.

Specialists advise that anyone possessing older 50p pieces should examine their designs closely, as uncommon versions such as this Blue Peter coin can be worth considerably more than their standard face value.