Kiwibank is warning customers after it was affected by a skimming operation in different parts of the country.
Kiwibank spokesman Bruce Thompson said that skimming devices had been placed on ATMs over the past two to three weeks in the Rotorua and Tauranga regions.
"The people doing this have been placing the devices on ATMs for a few hours and then removing them to capture information to clone cards," he said.
The police are working with Kiwibank, Thompson said, but he could not be specific about details for security reasons.
Thompson also said people should be careful when entering their PIN on ATMs, as they were aware of some cases where people have been standing close by and observed the PIN.