A Barclays employee acted as an inside man for a criminal gang which attached a piece of hardware to a computer at the branch where he worked and used it to steal £1.25 million, a court has heard.
Southwark Crown Court was told that Duane Jean-Jacques helped the crooks connect a keyboard video mouse (KVM) device to a computer at the Swiss Cottage branch of Barclays last April.
The device enabled the gang to access the branch's computers remotely. They are then accused of using Jean-Jacques' login details to make 128 transfers from six business accounts.
The court was told that when police searched defendant Lanre Mullins-Abudu's home they found a paper note in his toilet cistern with a "crib sheet" of people's compromised personal banking data as well as a KVM switch with a mobile router attached.
Jean-Jacques, Mullins-Abudu and three other men are on trial for fraud and theft-related offences.
Mullins-Abudu is also accused of taking part in an a similar attempted heist on a Santander Bank branch in September. On that occasion, a man - not currently on trial - allegedly posed as an engineer from BT OpenReach to get access to a restricted area of the branch and attach a KVM device.
Jean-Jacques, Mullins-Abudu and the other three defendants deny all the charges. The trial continues.