It's claimed fake Covid notices are being erected outside schools and public buildings, purporting to be from the HSE.
The signs include HSE logos and a QR code, which leads people to links containing misinformation about Covid-19 vaccines and other conspiracy theories.
Homeowners in Dublin are also reporting receiving newspapers and leaflets through their letterboxes, with false details about the pandemic.
Fine Gael TD for Dublin-Rathdown, Neale Richmond, says schools have had to warn parents about the notices: