A batch of fake Manx £20 notes are in circulation in the island.
A police spokesman said: ‘The notes are printed on inferior quality paper and the edges are not cut uniformly.
‘On some of the notes there is a visible, black vertical line evident down the right hand edge of the note (when viewed from the rear side).
‘Please contact us at police headquarters via 631212 if you have any information or are passed one of the counterfeit bank notes.’