Jinal Pethad used the 'Dridex' Trojan malware in the scam, which involved the 29-year-old acting as the "personal bank manager" to money launderers Pavel Gincota and Ion Turcan.
He set up 105 sham bank accounts for them using false identity documents.
Pethad pleaded guilty to conspiring to launder money between 2014 and 2016 at the Old Bailey court here last week and was sentenced to six years and four months in prison.
"Jinal Pethad abused his position of trust at the bank to knowingly set up sham accounts for Gincota and Turcan, providing a vital service which enabled them to launder millions," said Mark Cains from the National Cyber Crime Unit at the UK's National Crime Agency (NCA).
"Using his knowledge of the financial system, he made sure the stolen money was not blocked before entering these accounts, and provided the pair with reports to evidence his efforts and maintain the criminal relationship," he said,adding that the NCA is determined to work with industry and law enforcement partners to target cyber-crime at every level.
"We are determined to disrupt the flow of illegal money to prevent it funding further criminality," Cains said.
Pethad managed the accounts of the launderers to ensure that receipt of the stolen funds was not blocked by the bank's security processes and that the pair could transfer money between them freely.
During a search of his home in Edgware, north London, NCA officers recovered over 4,000 pounds in cash, seven luxury watches and three mobile phones, all of which had been used to communicate with Gincota.
Multiple text messages on one of the phones showed Gincota making arrangements to open new accounts and asking Pethad to change details, such as addresses and security information, on existing ones.
In one of the exchanges, Gincota asks: "Can I bring 2 guys for open acc pls??? 1-german; 1-france; or 2-france;(sic) who u want? Let me know pls!".
A Barclays spokesperson said, "We have worked with and supported the police with this investigation and welcome the outcome of the proceedings. Barclays has a zero tolerance to any unlawful activity and confirms Jinal Pethad was dismissed by the bank.
"We will always support law enforcement in identifying criminal activity and have no hesitation at all in supporting prosecutions," it said.
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