Police in the north-central Idaho city of Lewiston say they're investigating a possible counterfeiting ring after finding four phony $10 bills.

Lt. Budd Hurd told the Lewiston Tribune that the bills had the same serial number and were used over the last few weeks at various local businesses. Hurd says counterfeit bills have also been turning up in Orofino.

He says police have a suspect but no arrests have been made, and they're looking into the possibility that either there's a counterfeiting ring in the region or people are sharing money.