Queensland Police is investigating two sophisticated card skimming devices that were found attached to ATMs in a Brisbane city shopping centre last weekend.

The devices, which had only previously been seen before in Europe, contain an integrated pinhole camera designed to film the user entering their PIN.

"Previously what they would have would be ... a camera from a mobile phone. It would be secreted in a facia plate above the pin pad for the ATM and that was to record the PIN number going in," Queensland Police's fraud and corporate crime group detective superintendent Brian Hay said.

"This time however they've integrated a very neat little camera into a very small pinhole [on the device]."

Hay said the device was secured to the card slot with double-sided tape. One of the devices was partially dislodged by a "curious customer", who called police.

"We soon established that we had card skimmers in town," Hay said.

"We know that money has actually been extracted from compromised accounts already whilst the offenders are actually still plying their trade in Australia."

Hay warned that the impact of skimming was greater than victims of the devices often realised.

"People think that when their card is skimmed, they lose their money, the money's returned by the bank, the game is over, everything's good," he said.

"Everything's not good. The reality is the crooks now have your bank account number. They now can determine which bank issued your card.

"They now have your identity, and that's just the starting point."

Hay said bank details could be linked to other information on the internet to establish a more complete profile of a person's identity, information which could be onsold.

Queensland Police urged ATM users to take "simple security actions" when using machines, such as covering the hand you use to enter the PIN number, to ensure no one can watch.