Sylvania Township police are looking for the person responsible for attaching an electronic device that reads debit card and PIN numbers to an ATM, officials said.
The device, a skimmer, was found on the Fifth Third Bank machine on West Central Avenue near King Road on Saturday by a customer who then reported it to police, said Deputy Chief Ray Carroll.
The deputy chief declined to say how long the device had been on the machine or how many customers were affected.
Carla Nowak, a spokesman for Fifth Third, said in an emailed statement: "Our Fraud Detection team is contacting affected customers to alert them to the potential problem."
Because of the investigation, she said she could not release additional information about the skimmer.
The statement said customers with unauthorized transactions will receive full refunds as well as any associated fees; the affected customers will also be issued new cards and PIN numbers.
Deputy Chief Carroll said the skimmers are not always easy to spot unless you know what you're looking for, but he encourages people to contact authorities if "something doesn't look like the original equipment."
Ms. Nowak's statement echoed the chief's comments, saying customers should inspect machines before using them, looking for unusual signage, card readers that look out of place or improperly installed, and traces of "durable tape" or glue.
In 2007, authorities found skimmers on two Sylvania Township ATMs -- one on a Fifth Third machine and the other at a KeyBank.