A RARE silver coin discovered by a Wiltshire metal detectorist is being evaluated at the British Museum, writes Alice Clarke.

Jonathan Brooks, from Chilmark, found the artefact last October following a shoot of the BAFTA award-winning BBC series Detectorists, where he featured as an extra and on-set advisor.

After the shoot, Jonathan returned to Essex with writer and director Mackenzie Crook to give him further experience of detecting.

The coin was among the artefacts found that day.

Jonathan told The Searcher magazine: “It wasn’t until the end of the day I realised it was solid silver and could be a bit special as it was not in my reference book."

The find has now been identified as a silver denarius of Carausius, minted between 286 and 293 AD, and is pierced, which could mean it is declared treasure.

Expert Sam Moorhead, national finds advisor for iron age and Roman coins, told The Searcher magazine: “It is rare, it’s the only example with this reverse legend and type.”

The coin is being examined in the British Museum to determine its exact rarity and worth.