A sophisticated skimming device has been found attached to a cash machine in Hamilton.

Sergeant Brendon Davis of the Waikato Tactical Crime Unit says it was concealed by a green overlay, which sat on top of the green sleeve where people slide their cards in.

He said a panel had also been added to the machine.

"Inside the panel had a pinhole camera so the green sleeve recorded the details of the card whilst the pinhole camera recorded the details
of the pin number. They could put the two together and use the cards."

Davis warns people should cover their hand when they're putting PIN numbers in, to stop hidden cameras catching the details.

"Whilst the technology is relatively simple, it's more sophisticated than we have had previously and we've had an operation some time ago where we had some overseas nationals who brought the technology to New Zealand and had put them in a number of places around."