A bus driver is warning people to be vigilant at cash machines after he found three 'suspicious devices' at a NatWest branch in Morden.
Duane Alloway said he detached the devices from a cash machine at the Crown Lane branch after spotting them when trying to withdraw money from his bank account.
He is warning people to be on the look-out to protect themselves from attempted fraud.
A NatWest spokesperson encouraged people to report anything suspicious to them immediately and Metropolitan police officers are investigating.
Mr Alloway said: "I saw it because it trapped my card.
"I put my Pin in and it rebooted so I thought it was odd.
"I looked at it and there were three chevrons leading to the card slot.
"I tugged it and it came off in my hand.
"This can't keep going on."
After he spotted the first device in December last year, he went on to spot two more at the same cash machine.
Mr Alloway, of Byne Road, Carshalton, reported the finds, that occurred over several weeks between December and February, to the branch and alerted police officers who began an investigation.
He said the three devices differed in appearance, and could be used to spy on people entering Pin numbers and personal account details.
A NatWest spokesperson said: "ATM fraud is an industry wide issue that NatWest take very seriously.
"We would advise anybody who notices anything suspicious about one of our cash machines to report it to us immediately.
"We are working closely with the police and other local organisations in Morden to reduce the likelihood of this type of attempted fraud."
Police confirmed they had received a report from a male driver who was passing NatWest, Crown Lane, Morden, at about 5.30am when he spotted a device fixed to the bank’s cash machine.
If you have seen anyone fitting a device to this cash machine, contact Sutton Police station on 101 quoting reference no: 1415485/13. Or contact Crimestoppers anonymously on 0800 555 111.