Four men appeared in court Saturday, charged with attempting to rob a bank by taking control of its computer system.

Police say the suspects were arrested after a bogus maintenance engineer tried to install a keyboard-video-mouse _ a device typically used to control several computers at once _ on a computer at a south London branch of Spanish bank Santander.

Detectives say the hardware could have "allowed the suspects to take control of the bank's computer remotely," and potentially allowed them to siphon millions. The suspects were arrested before any money was withdrawn.

Lanre Mullins-Abudu, Dean Outram, Akash Vaghela and Asad Ali Qureshi, aged 25 to 35 and all from London, were charged with conspiracy to steal. They spoke only to confirm their names at a brief court hearing. A judge ordered three of the suspects detained until their next court appearance on Sept. 27, and freed Vaghela on bail until the same date.

Eight other suspects have been released on bail pending further inquiries.

Santander said none of its staff was involved in the attempted heist, the latest case in which a bank has been targeted by tech-savvy criminals. U.S. investigators announced in May that a gang operating across 27 countries managed to steal $45 million in two separate sprees after compromising payment systems used by two Middle Eastern banks.