Police are warning shoppers and traders to beware after forged £20 notes were found in King's Lynn.

The fakes are copies of notes issued by the Royal Bank of Scotland (RBS).

Lynn police tweeted: 'We are investigating a couple of instances where fake Scottish £20 notes are being used in the town centre. Please be vigilant.' The RBS has guidelines on spotting forgeries. They say: 'Genuine banknote paper should be reasonably crisp and not limp, waxy or shiny and the special printing processes give banknotes an individual feel. It should not feel like normal paper.

'Raised print is used in some of the features on genuine banknotes and should feel slightly rough to the touch.

'Lines and print should be sharp and well defined with no blurred edges. Colours should be clear and distinct – not hazy. The wording on RBS banknotes is in raised print.'

Earlier this year similar forgeries were found to be circulating in Diss.