Twelve people have been arrested for allegedly laundering money stolen from bank accounts through so-called "phishing" scams.
"Phishers" are usually based abroad and need accomplices in the UK
Six men and six women from Estonia, Latvia, Lithuania, Russia and the Ukraine are suspected of transferring the money on behalf of a Russian gang.
Computers, passports, chequebooks, bank cards and crack cocaine were seized during raids mainly in London.
Phishers pose as a bank and then e-mail customers asking for personal details.
The information obtained through the bogus security check is then used to siphon money from the victim's bank account.
The National High-Tech Crime Unit (NHTCU), specially created in 2001 to deal with cyber crime, carried out the raids at addresses in Edmonton, Shepherds Bush, Stoke Newington, Streatham and Tottenham in London, as well as Ramsgate in Kent.
The suspects are believed to have acted as intermediaries in the UK, as phishers are usually based abroad and cannot transfer money directly overseas.
The were allegedly recruited by Russian organised crime gangs to open up accounts from where the stolen money was eventually transferred to Russia - an operation for which the criminals had to pay a 7% commission.
The deputy head of the NHTCU, Det Supt Mick Deats, said: "Organised crime is targeting Internet users, and specifically Russian-speakers, in the UK to launder money stolen from online bank accounts where people have been duped into handing over their account details.
"We believe this gang has sent hundreds of thousands of pounds back to Russia," he added.
"They have targeted a large number of high street and Internet banks, and because they are unable to break into the banks' systems themselves, they are resorting to duping account holders into parting with their details."