Using these notes can bring a potential prison sentence of 10 years.
Gardai are warning there's been a significant increase in the amount of fake "movie prop money" in circulation.
This comes after an amount which represents €430K has been seized in recent months.
Gardai are now warning businesses and anyone who deals in cash to be vigilant and watch out for the fraudulent notes.
They bear a strong resemblance to genuine notes, but do not have the security features.
They're also usually marked as "movie money" or "prop money".
It is an offence to use these notes to buy something, and carries a potential prison sentence of 10 years.
Gardai are advising businesses to report anyone they catch trying to pay with "prop money" to them immediately.
