Officers investigating reports of counterfeit notes in Newport have appealed for local businesses to be vigilant.
Police received seven reports on Monday 15 June of fake £20 being used at shops in Newport.
A 37-year-old man and a 33-year-old woman, both from Newport, were arrested on suspicion of using counterfeit money.
They have both been released from custody but remain under investigation.
Inspector Terry Clawson said: “We have been made aware that there are counterfeit £20 notes in circulation on the island.
“If you are handling money, please make sure you check it thoroughly and report any fake notes to us.
“There are lots of resources available to help you identify a counterfeit note, and we urge all businesses to ensure they know what to look out for.
“We take fraud very seriously and any reports of counterfeit money will be investigated.”
Anyone with information can phone 101, quoting the reference 44200215789.