The Metropolitan Police have foiled an extraordinary plot to steal millions of pounds from a London branch of Santander Bank using a remote control device planted on one of its computers by a bogus maintenance man.On Thursday evening, the Police's Central e-Crime Unit (PCeU) arrested 12 men between the ages of 23 and 50 years old accused of being involved in the alleged attempted heist at addresses in London, a statement said.Police appear to have been monitoring the gang for some time, swooping when it became clear that a theft might be about to happen from the Surrey Quays branch of Santander Bank in London.A bank source confirmed to press that a KVM (keyboard, video, mouse) was fitted by someone posing as a maintenance worker, something that would have allowed the gang to control that machine remotely from inside the bank's network.KVMs are normally used to switch between two or three desktop computers sharing the same keyboard, mouse and monitor but this fraud was carried out using what appears from a police photograph to be a wireless extender allowing the setup to be controlled from a distance."This was a sophisticated plot that could have led to the loss of a very large amount of money from the bank, and is the most significant case of this kind that we have come across," said Detective Inspector Mark Raymond of the PCeU."I would like to thank our partners from the industry who have provided valuable assistance throughout this investigation," he said.A Metropolitan Police spokesperson confirmed that this was the first time such an unusual technique had been used in the UK by an organised criminal network."The attempt to fit the device to the computer in the Surrey Quays Branch was undertaken by a bogus maintenance engineer pretending to be from a third party. It failed and no money was ever at risk. No member of Santander staff was involved in this attempted fraud," read a statement by a Santander Bank spokesperson."We are pleased that we have been able, through the robustness of our systems, to prevent the fraud and help the police gather the evidence they needed to make the arrests. Santander operates multiple levels of controls to protect customers' funds and this attack would not have been successful."Security firms will point out the scale of cyber-attacks on banks but this conspiracy sounds more like an old-fashioned bank job using technology as a sort of digital door.An interesting parallel for the latest case might be a $5.2 million raid on a South African bank in 2012 that is believed to have used similar remote control technique to initiate transfers to accounts which were then emptied via ATMs.