For the scam to succeed, the fraudster needs a UK-based mule to receive money into his or her bank account, then withdraw it and send it overseas using a commercial money transfer service.
The banks have put out a fraud alert in the London Borough of Newham (see my BBC report), where they are monitoring over 1,500 suspicious bank accounts. They could belong to money mules.
23 year-old Barbara Gyami from Newham told me how she had a lucky escape...
"I am currently unemployed and I registered with jobsites and agencies. I received junk email. Six or seven were from a particular address. They said they had a particular job and that I would have to give them my bank account details.
I would only be working for 5 to 6 hours a week and I'd be paid between £1,500 and £2,000 a week. It sounded too good to be true. They had said that I would have to handle £6,000 a week in my account.
I emailed them back and they replied with a contract attached. Then I contacted my job adviser. She said I should be very vigilant.
I phoned their number and no one answered. I thought: how come you haven't got any offices or anyone to answer the phone?
I didn't know what they might have done with my account. They're still sending me emails.
Then Newham Council called me. They were doing a survey about these people. They told me it was illegal."