Summer 2013 - unsuspecting Brits are flying into a crimewave in Spain.

You're constantly like, where's my bag?

Is my zip open? ls my pocket open? Who's that standing behind me?

A new type of pickpocket, more brazen and cunning than ever before,

armed with an array of new criminal tricks, is targeting the unwary.

The reptile is a particularly sneaky pickpocket

and he will target you whilst you're having sex on the beach.

Professional dippers who know how to play the system.

You can quite happily go through the day stealing from people

and nothing will happen to you.

Next thing I know they're running off and that was me wallet gone.

They're absolute vermin. Scumbags. Absolute scumbags, they are.

We have exclusive access to the undercover police,

as they attempt to fight back.

And we're with a hardy group of expats...

Rickshaw taxi!

..with their unique ways of trying to protect their fellow Brits.

I'll physically stop pickpockets from getting on a train

when they're about to put their hand in someone's bag.

You see it all the time and you try and stop it if you can stop it.

For Brits abroad,

Spain is the most likely place in the world to be dipped.

And there's a warning to Britain.

All of the pickpockets say that they want to go to London.

With London the number one destination for European tourists

and just a short flight away,

the UK's a tempting destination for the East European gangs.

Barcelona,

home of Gaudi and alfresco dining,

draws over 1.5 million British tourists every year,

many of whom are blissfully unaware that they are attracting

a certain type of criminal.

The pickpockets are targeting the British tourists

simply because they view them as having a great deal of money.

You don't have to be rich in our country

to be considered rich by these guys.

The Brits are the biggest foreign spenders in Spain, parting with

over 4.5 million euro first six months of this year alone.

Which makes them a target for some of the most unscrupulous

pickpocket gangs in Europe.

So London, yeah, that's got its dippers,

Paris has got plenty of pickpockets, but Barcelona at the moment,

they're in the Premier League, they're the dons of the trade.

The Montjuic Park area of Barcelona and a team of undercover

police officers are on the trail of two known pickpockets.

These are the two suspects in a queue of tourists.

This police officer, posing as a tourist, is waiting to pounce.

But he can only stop the men if he sees them attempt a dip.

When pickpockets work in pairs,

one will do the dip whilst the other one carries the goods away.

This ensures they don't get caught red-handed.

The undercover j the two suspects to an outdoor cafe.

A closer look reveals the man in purple to be Ley Karavan,

a known pickpocket from Romania.

Right now.

The suspects move off towards the Olympic Stadium.

Under Spanish law, convicted pickpockets can only receive

a prison sentence if they are found to have stolen 400 euros or more.

Any less, and the most the offenders will get is a cautionary fine.

From that position we have the view of the two.

Now, the nervous wait

for the two pickpockets to make a move on a tourist.

Ley and his accomplice move in.

A hand goes into a bag and they move away.

It's just what the police have been waiting for.

Ley and his friend are detained, whilst the police officer tries

to explain what has happened to two rather confused British tourists.

He... He opened the bag. He opened the bag.Yes. Goodness!

Where are you from? Er, well, we're from England,

but this fella came around and I thought this fella's attacking him,

there's some private disagreement.

I never even noticed these guys.

I... I... I lost sight... You know, I wasn't even looking at that.

Don't get excited, Peter, don't get excited.

The police search the men,

only for Ley to offer to expose himself to the cameras.

This time, the tourists escape without losing any money.

Good news for them, but not necessarily for the police.

All they can do now is bail the pickpockets to appear in court,

where the most punishment they can expect

is a statutory fine of between 100 and 300 euros.

Pickpocketing is a professional game.

Like any other business, it's about risk and return.

You steal 300, you get fined 100, so what?

In 2012, almost 2,000 British tourists were robbed in Barcelona.

Faced with such a challenge,

an unlikely group of expats have decided to take on the dippers.

Mates Danny, Mike and Pete relocated from Liverpool to Barcelona

four years ago and now work as rickshaw drivers on the seafront.

Welcome to our office.

Who doesn't like a nice, friendly pair of Scousers

who AREN'T out to rob them?!

Recently, the intrepid chauffeurs have taken it upon themselves

to try and protect the tourists against the dipper gangs.

They're absolute vermin.

I'm disgraced by it, like, because you're dealing with it every day.

just one warning, really.

There's lots of thieves operate on the beach, so just be careful.

Always look after your bags and keep them in front of you.All right.

Rather than behind. Hey, buddy.

I just thought I'd warn you that there are a lot of thieves

who are operating here and if this is even just slightly

out of sight, they could whip it really quick and escape on a bike.

Thank you. No problem.

It could be the first day of the holiday.

They get this little bit of time to go and enjoy themselves and there's

nothing worse than having that taken away from you right at the beginning.

Not surprisingly,

the dipper gangs don't appreciate the Scousers' campaign.

Wheeling rickshaws, we meet a lot of tourists who come through the city.

We were warning people off of the thieves,

as the thieves were stealing their things and the thieves came up to us

and threatened us directly and said, "This is my job.

"You do your job and we'll stay out of each other's way."

And that was a pretty direct threat

and it meant that there's a lot of us,

sometimes we are carrying knives, and things like that,

so don't mess around with us.

Hola! ALL:Hola!

The trio have now developed more subtle methods of warning tourists.

If I see a guy coming up, I'll just go...

RINGS BELL LOUDLV ..rickshaw taxi!

And then the person turns around, sees the guy going for the bag,

and at least I've warned them, in my own kind of way,

without going up to them and saying,

"You're going to get robbed," do you know?

I've seen these guys since I've been here.

God knows how many times I've seen them being arrested.

But there's four guys and they're looking down onto people

and they're sussing things out.

Danny has just spotted four men he believes to be

a gang of working pickpockets on the seafront.

We'll just follow them behind and, hopefully, we'll catch something.

They're actually going down to the beach now.

They're looking for people who they can pick off,

who have gone into the sea, left their bags unattended

and they've obviously spied something, so they're heading down,

so I think we should go over and see if we can catch something.

They're definitely up to something.

They're talking to people on the rocks.

They've got groups of people on the rocks.

To catch them in the act would be absolutely fantastic.

Go, "There you are. Show that to the police."

The gang realise they are being observed.

A man raises his hand in recognition.

But at least one group of tourists and their wallets have been saved.

In Barcelona, the pickpocket will use every means possible

to get at the valuables of unsuspecting British tourists.

Probably, my favourite scam in the history of scanning

is the midget-in-the-bag scam. Brilliant.

This took me by surprise, about the level of ingenuity

I'm seeing in the mind of the thieves.

This is Miquelon, whose name means "Big Miguel".

He's the key to the most ingenious theft scam ever.

Take it away, Miquelon.

The man-in-a bag scam involves a small person,

or a contortionist, who is able to climb inside a tourist travel bag.

This coach is packed full of tourists and their valuables,

which are safely in the hold.

Or so they think.

Miquelon is out the bag, surrounded by tourist treasure,

and his pilfering hands are hard at work.

He's back in the bag and no-one even knew he was there.

But this isn't the only cunning trick designed

to part tourists from their cash.

Coming up, the devious new tricks being played on British tourists.

The mute petition is a beautiful scam.

The consul official who tries to pick up the pieces...

Keep your wits about you and get a bag with a zip.

..and the dipper gangs move down the coast to the seaside resorts.