Police are urging people in Builth Wells to be on their guard after an increase in reports of counterfeit £20 notes being used in the area.

Dyfed-Powys Police has issued the warning ahead of the Royal Welsh Show, which will attract thousands of visitors to the town next week.

Officers are reminding the public and local businesses to check banknotes carefully, with genuine polymer £20 notes featuring a number of security measures.

These include a hologram which changes from the word “twenty” to “pounds” when tilted, a multicoloured holographic area, and raised print on features such as the words “Bank of England”.

Police said fake notes may have holograms that do not change, silver-looking holographic areas, incorrect texture or thickness, or holographic patches which appear glued on and out of alignment.

The force has also warned people to be aware of “prop notes” – imitation notes which can contain words such as “prop” or “copy” covered by foil stickers to mimic security strips.

Even without the foil sticker, these notes are deemed counterfeit under UK legislation.

Possessing or using counterfeit currency is a serious offence and can lead to a prison sentence of up to 10 years and an unlimited fine.

Anyone with information about counterfeit notes is asked to contact Dyfed-Powys Police on 101 or report it online. Anonymous information can also be passed to Crimestoppers.

You can find more advice on checking your bank notes via the Bank of England website.