It is so well hidden you would never notice it was there – but it could cost you thousands of pounds.

Police have discovered a tiny camera hidden in ATM machines that records unsuspecting members of the public’s credit card details.

Hidden within a false cover on the machine, the pinhead-sized camera enables fraudsters to film people entering their pin numbers.

A similar device was found above another ATM in central London (City of London Police)

The device was discovered at a cashpoint in St Paul’s Churchyard in the City of London on 18 February. Two weeks later, a similar device was removed from another nearby ATM by a member of the public.

At least two further ATM cameras have been discovered in the area in recent days. Police are investigating the matter but have so far made no arrests.

One device was removed by a member of the public, revealing the recording equipment underneath (City of London Police)

“The vast majority or cashpoints in London are perfectly safe - but criminals have been known to tamper with them”, said PC Matt Clarke from the City of London Police Crime Squad.

“We work closely with banks, building societies, and other cash machine vendors, to make sure this type of crime doesn't happen.

“Take care and stay vigilant when using cash machines in the City of London, and London as a whole. If you spot anything unusual about a cash machine, or if there are signs of tampering, don’t use it. If in doubt, try and use a machine inside a branch.”

Police said people should 'take care and be vigilant' (City of London Police)