Beware the scam disguised as a job offer
So how can you spot it, and who is most at risk?
The scamThe scam begins with an email, which is spammed out to hundreds of thousands of email addresses. These can be plucked from thin air, or accessed by trawling through CVs posted on internet job boards.
The jobs offered are called things like "payment processing agents" or "administration assistants".
They look like bona fide jobs, but essentially involve the payment of the proceeds of crimes into your bank account. You then pay the cash into an overseas account, effectively hiding the money and laundering it for criminals. In return you receive a share of the money.
ConsequencesFFA warns that this activity is illegal and carries a number of consequences. You could have your bank account frozen; you could have trouble opening an account in future - which could mean you struggle to get a mortgage or insurance. In some cases, you could be prosecuted and go to jail for up to a decade.
The experts say that those most at risk of falling for these scams are hard-up job-seekers. These include students and recent graduates as well as unemployed people. As part of its research FFA found that 19% of all students who had been approached had signed up - compared to 6% overall, and 13% of unemployed people.
The group concluded that 380,000 people could have fallen for the scam.
DangerousDCI Dave Carter, Head of the Dedicated Cheque and Plastic Crime Unit said: "What might initially seem an attractive method of boosting your income during tough times is in reality the work of determined international criminals, aiming to turn the public into an unwitting army of accomplices to fraud."
"These new figures demonstrate the gap between perceptions of the public and the real seriousness and criminality of this conduct. Whether through naivety or 'willful blindness' to the consequences, members of the public need to reject any approach for their bank account to be used in this way."
Spot the scamMoney mule adverts or offers can take a variety of different forms and they may even copy a genuine company's website and have a similar web address to make the scam seem authentic. You need to check any offer out very thoroughly. Sometimes the quality of the English or grammar will give you a clue that this is not an authentic advert.
These adverts will normally state that they are an overseas company seeking 'UK representatives' or 'agents' to act on their behalf for a period of time, sometimes to avoid high transaction charges or local taxes. This is a clear signal they are asking you to break the law.
The nature of the work that the company will claim to be involved in can vary, but the specifics of the job being advertised invariably mean using your bank account to move money
FFA says that it's always sensible to be cautious of unsolicited emails promising opportunities to make easy money. If you receive one, at the very least you need to verify any company that makes you a job offer and check their contact details (address, landline phone number, email address and website) are correct and whether they are registered in the UK.
They recommend being careful of those offering jobs who are based overseas, as it is harder to check they are legitimate.
Finally, they say never give your bank account details to anyone unless you know and trust them. If you have already disclosed your bank account details or received money into your account and you think it could be a money mule scam, you should contact your bank immediately.