Videos online appear to show a fake QR code sticker on machines to allow drivers pay for parking via their phone.
Motorists are advised not to scan any QR codes or barcodes that may appear on parking metres.
If someone inadvertently scans the QR code, they are then brought to a fraudulent website which requests credit card details and other personal data.
Instead motorists are asked to download the parking app Payzone.
It’s understood one woman in Greystones was scammed out of €1,000 after mistakenly scanning one of these QR codes.
Gardai say they are monitoring the situation.