There are fears that personal bank details may have been stolen after ‘snooping devices’ were found plugged into public computers at libraries in Wilmslow.

Police are investigating after the small gadgets were spotted attached to keyboard sockets at the back of two machines in Wilmslow and Handforth libraries. It is not known how long they had been there.

Two devices were seized by library staff and are being studied by Cheshire police’s hi-tech crime unit.

However, a third device disappeared from Wilmslow library before it could be confiscated.

It is now feared people may have had details of their bank accounts, passwords and other personal information stolen.

The devices, which look like USB drives, are legal but may be used to intercept and steal people’s personal data, which is a crime.

Nathan Evans, manager of Fathom IT in Wilmslow and North Cheshire, said: "These are pretty horrendous things. They are a key logger so they record anything that’s keyed in – passwords, bank details, everything.

"So, if someone goes along to the library and decides to book a flight or buy something off Amazon, you’ve got a big problem.

"They are essentially a fraud device and have been used in some massive frauds before."

Security has now been stepped up with frequent checks being carried out on all computers and keyboards are now being plugged into the front of machines, making such devices easier to spot.

Coun Andrew Knowles said: "We take this matter very seriously indeed and are now awaiting police reports on their findings.

"The vigilance and swift actions of our staff is to be commended but we will not be complacent.

"We will take all practical steps necessary to protect people's privacy and personal details and I urge the public to help us by being vigilant and sensible when using public computers at all times.

"If users have any concerns, they should alert our staff immediately."

Insp Matt Welsted said: "This is an example of how criminals have changed over the years to take advantage of technology and social trends.

"The good news is that incidents such as these are still very rare and easily prevented. If you think something is suspicious, then challenge it and tell us about it."

Anyone with information, or who fears their personal details may have been used or taken, should contact Cheshire police on 0845 458 0000.