Police in Tauranga are warning retailers to be extra-vigilant when handling cash, because counterfeit notes are circulating in the area.
Senior Sergeant Glenn Saunders says a variety of different businesses have reported people trying to swap fake $10 and $20 notes for $50 or $100 notes in the past few days.
He says the counterfeit notes are smaller than normal, the Queen's face is missing from the watermark, and the silver fern and dollar amount are missing from the plastic segments.
Mr Saunders says police are following strong leads, but are urging retailers who see the counterfeit notes to contact them immediately.