The coins which are legal tender in the United Kingdom all have a face value of £0.50 ($0.60/€0.57).

Those advertised on the sales platform eBay feature the portrait of the late Queen Elizabeth II.

Designed by Alex Loudon, the reverse features a cyclist and athlete "depicting the power of sport," together with the inscription "XX Commonwealth Games Glasgow."

The lettering was inspired by Glasgow-born architect, artist and designer Charles Rennie Mackintosh.

The specialist coin website Changechecker estimates that some 6.5 million coins with the design were produced.

Coins of the same face value from the London 2012 Olympics were released in different quantities for each sport.

A rare coin with an original aquatics design with waves across the swimmers face had been known to fetch more than £1,000 ($1,200/€1,135) because the design was later modified.

The 50 pence coin was introduced to circulation in 1969, two years before Britain adopted a decimal currency system.

It was said to be the first seven sided coin in the world.

The first coin produced to celebrate the Modern Olympics was the 500 Markkaa piece produced to mark the 1952 Helsinki Games.

The website Coin Catalog has estimated that they would fetch up to $500 (£415/€471).