Nigerians Gboyega Akinbola, 36, and Oyetunde Oyedeji, 31, went on a spending spree worth an estimated £60,000 after buying the credit card details of more than 1,100 people from an international hacking syndicate.
The pair, who had registered as students after arriving in Britain, were only caught when Moss Hills, owner of the Stagebeat music store in Guildford, Surrey, noticed Akinbola’s delivery address was different to the one on his card details and became suspicious.
Launching his own investigation he managed to trace an email address for Akinbola, hack into it and uncover evidence of widespread fraud.
He then passed the information onto Surrey Police and the Serious Organised Crime Agency (SOCA), who launched Operation Prince to smash the international network.
The investigation uncovered a vast scam involving more than 200,000 stolen credit card details and leading to the biggest retrieval of compromised data in UK law enforcement history.
Two of the alleged ringleaders of the conspiracy were later picked up by police at their homes in Egypt and Vietnam.
Jailing Akinbola, from Barking, Essex, for three-and-a-half years and Oyedeji, from Woolwich, south-east London, for two years at Southwark Crown Court, Judge Christopher Hardy said the investigation had uncovered a “shocking hole in the banks’ credit system”.
It is believed hackers around the world had been able to steal credit card details including passwords from British banks before selling them on to criminals, including the Nigerian pair.
Judge Hardy said Mr Hills should be recognised for his “ingenuity”, awarding him £500 reward from the public purse.
He also recommended Akinbola’s deportation but made no such order against Oyedeji, who married a woman with UK citizenship and has been given leave to remain as a student.
The court was told that Akinbola also entered the UK as a student and worked as a night time security officer.
He also tried to enter into a sham marriage to secure his status in the country.
Akinbola and Oyedeji pleaded guilty to charges of fraud, admitting the plot totalled around £30,000.
Detectives believe the total figures could be much higher however.
Trevor Pearce, Executive Director of SOCA, said: “As a result of national and international co-operation, SOCA was able to dismantle a worldwide organised crime network dealing in huge quantities of stolen credit card data. This was an excellent operation that resulted in the biggest retrieval of compromised card data in UK law enforcement history.”