I was a teenage 'money mule'

"Have you ever held £2,000 at once in your hand?" that was the line used to tempt Holly into becoming a money mule.

At the age of 17 and still at school, Holly (not her real name) was approached on Instagram, then Snapchat, by a person who promised to pay her a decent sum, if she let him use her bank account to move money.

Even though she knew this was suspicious, Holly eventually handed over her bank card to a young man who was essentially a stranger.

"He was convincing me. He showed me other people that he's worked with about how much money they got and he just kept on pestering me for my card and I just eventually gave in," she told BBC Radio 4's Money Box programme.

The deal was apparently simple. Holly would receive money into her bank account and then transfer it to another account or take it out in cash and give it to someone. In exchange she would get a cut of the money.

But by becoming a money mule, what Holly was really doing was laundering the proceeds of crime. It's a serious offence, and if caught money mules could get a maximum sentence of 14 years in prison.

Holly is by no means alone in doing this. According to Cifas, the UK's fraud prevention service, in 2017 its UK member banks identified 8,500 money mule accounts owned by people under the age of 21 - some owned by teenagers as young as 14.

What's worrying is that young people under the age of 21 are the fastest growing age group being recruited by criminals to launder money in this way, up 36% on 2016.

Holly's story shows how common it is becoming.

"It's like an everyday thing for me, it's normalised where I am. Because the way it's around me, I forget that it's even illegal, what everybody's doing."

Holly describes how the people around her, the "Fraud boys" or "Fraud stars" as they're called, have developed a unique language on social media to tempt people in.

"I see it on my social media, people asking who has this card, who has that card. For Barclays, they say Barks, for NatWest they say Natty, for Santander they say Sants.

"They call cards squares. So who has a Natty square, 5K drop, which is basically £5,000 will be put in your account, and you'll get a cut."

In Holly's case, her card fell into the hands of a man who put £1,500 into her account, under a fake company name. Holly was instructed to go into the bank and withdraw the full amount. But things didn't go to plan.

The bank started asking her detailed questions about the company that she had to pretend she worked for, and then they asked to see the manager of the fake company in person, to verify that he had put in the money.

The whole time, the man organising the fraud was standing across the road looking in, and communicating with Holly by text, telling her what to say.

"I was nervous and, sort of scared, in case the bank man caught me out there and then. I never knew really what to say but I just had to lie and use my common sense or to think of something."

The fraud didn't work and Holly left the bank empty-handed. But then consequences of what she had tried to do kicked in. First, she lost her bank account entirely.

Then when she tried to apply to different high street banks they wouldn't accept her.

"Then that's when I sort of realised I could have been black-listed. I called one of them up they said 'there's a tag or message on your record'."

The message Holly is talking about is a Cifas "first party fraud" marker, which flags up the fact that her account was used for fraud to other banks. The marker will stay with her for six years and Holly is already struggling with having no access to banking.

"You don't realise how much you need a card or bank account until you actually don't have one." she says.

"It's hard for me to apply for jobs because some jobs say that you need your bank account to get an interview. I can't buy things online, I always need to give money to somebody and say, 'can you do this, can you buy that, can you buy this online for me?'"

Holly currently works part-time, where she gets paid by cheques. She cashes these in at The Money Shop, which charges an 8% rate and a handling fee, meaning she loses money each time.

Being locked out of banking is one punishment facing young people who make the mistake of becoming money mules, but what are the chances of going to prison?

The Metropolitan Police started looking at the issue in March last year and since then has been working to identify the criminals behind the money laundering and the so-called "fraud boy" recruiters to get them arrested and prosecuted.

Detective Chief Inspector Gary Miles from Metropolitan Police's Fraud and Linked Crime Online unit recognises that the problem is growing at a very alarming rate. His team have sent letters and police officers around to schools, warning them of the danger.

"It is not a problem we are going to arrest our way out of," he says.

"We don't want to give a whole young generation convictions when maybe they're at the start of their life and they've actually made a mistake. What we actually want to do is give them the knowledge, the skills and the powers to stop them making those decisions in the first place."

As for Holly, she feels angry with the people who got her involved, but mainly she feels angry with herself.

"I heard of people doing it and nothing had happened to them so I thought it wasn't going to happen to me. But it's my fault really.

"I just should have listened to my friends. They told me don't do it. I'm going to have to live with it for six years now."