UK and Irish police have today swooped on an international e-crime gang accused of attempting to steal money from up to 20,000 online bank accounts and credit cards in the countries.

Using initial estimates from the Metropolitan Police Central e-Crime Unit (PCeU), the unnamed five men and one woman arrested are accused of stealing £358,000 ($570,000), from 10,000 bank accounts and at least £3 million ($4.7 million) from a further 10,000 credit cards.

They are also accused of attempting to steal a further £1.14 million ($1.8 million) from online bank accounts.

The arrests are part of a larger PCeU investigation, ‘Operation Dynamaphone’, looking at a “network of suspects believed to have systematically obtained large quantities of personal information, such as online bank account passwords and credit card numbers,” the official release said.

Credit cards rings are a common criminal pursuit, but the scope of this accused gang appears to have been online only, which marks out the arrests as unusual. Online gangs are normally assumed to be more commonly found offshore in countries with weaker computer misuse laws than the UK.

"We have taken this action to shut down an organised criminal network running an online phishing and account take-over operation,” said PCeU Detective Inspector Colin Wetherill.

“A great deal of personal information was compromised and cleverly exploited for substantial profit. By disrupting the operation we have hopefully prevented further loss to individuals and institutions across the UK.”

The six accused, whose nationalities remain unknown, are currently being questioned in London.