A staff member noticed the device on the Lloyds TSB machine before 8:30 am on Thursday 20 May.  It was later retrieved by Selby Police who's officers describe the devive as a 'sophisticated item'.

It is believed it had been in place for around two hours.

The device has two parts, with the upper section being a stick-on silver fascia that is sited above the ATM keypad. Contained within this bar, measuring approx 12 inches, is a small camera connected to a power cell similar to a mobile phone and other electronics. A small aperture allows video of people keying in the PIN numbers. In turn it is believed that images are transmitted via bluetooth to a nearby recipient.

The second device is another bar that covers the original bank car slot. Again, a device is used to "read" the electronic strip and this too is transmitted to the receiver .

Sergeant Phil Holliday, of the Selby Safer Neighbourhood Team, said: "We are doing everything we can to track down the offenders. The forensic examination of the device should help to develop further lines of enquiry.

"I also urge anyone who recalls seeing any suspicious behaviour around the ATMs at Morrisons in the days leading up to Thursday 20 May, but particularly during the early morning of Thursday, to contact the police as soon as possible."

Customers are advised to carry out a visual inspection of any ATM they may use, as such devices do not interfere with the function, but do clone information from cards and PIN numbers can be compromised.

If customers are in any doubt, contact your bank to make sure there have been no fraudulent transactions on accounts.

If you have information that could assist the investigation, please call Selby police on 0845 60 60 24 7 quoting the reference number 12100080295.

Information can also be passed on anonymously by calling Crimestoppers on 0800 555 111.