London: British police said on Friday they have arrested eight men after a gang stole $2.09 million from Barclays bank by taking control of a branch computer system.

The men, aged between 24 and 47, were arrested on Thursday and Friday morning on allegations of conspiracy to steal from Barclays and conspiracy to defraud British banks.

They are accused of a theft in April, when a man purporting to be an IT engineer arrived at a Barclays branch in north London saying he was there to repair computers.

He then attached a keyboard, video and mouse (KVM) device with a 3G router to one of the computers, which allowed the gang to remotely transfer money into their bank accounts.

Such devices are routinely used by people in business to work remotely on their office computer systems, but have featured in increasingly sophisticated criminal plots.

Four men were charged last week over an aborted plot to take control of a computer in a London branch of Santander bank.

As part of their investigation into the Barclays theft, officers searched a number of addresses across London and Essex, east of the capital, and seized cash, jewellery, drugs, “thousands of credit cards” and personal data.

One site searched in central London was described by detectives as the “control” centre of the operation.

“Those responsible for this offence are significant players within a sophisticated and determined organised criminal network, who used considerable technical abilities and traditional criminal know-how to infiltrate and exploit secure banking systems,” said Detective Inspector Mark Raymond of the Central e-Crime Unit.

Barclays recovered “a significant amount” of the money stolen, police said, and the bank insisted that none of its customers lost out.

Alex Grant, managing director of fraud prevention, said: “Barclays has no higher priority than the protection and security of our customers against the actions of would-be fraudsters.”

He added: “We identified the fraud and acted swiftly to recover funds on the same day.

“We can confirm that no customers suffered financial loss as a result of this action.”