France: behind the scenes in the war on Romanian gangs

They arrive early in the morning in front of the Paris Opera, one of the busiest tourist spots in the French capital. But the 20 Roma children brought from Romania are not there to see the sights.

Armed with a notebook bearing the logo of a charity for the deaf and mute, they attempt to persuade passers-by to give them donations. But the charity doesn't exist, and the children aren't deaf or mute. The scam works quite well - some tourists give as much as 10 or 20 euros in notes. But the girls don't keep the money long.

The gang leaders are just a few yards away, keeping a discreet eye on operations. Every half hour, they gather the money collected by the children.

Meanwhile, other groups of children are taken to the very centre of Paris, where they split up along the main boulevards. They walk beside the cafes, snatching iPhones that tourists have left on the outside tables. Again, they use the fake petition as a decoy. One second is enough to distract the unsuspecting tourist, before both phone and children disappear in a flash...

Using a hidden camera, we found the stolen smartphones for sale at a market in a suburb in the east of Paris. A woman offers us the very latest model, normally sold at 800 euros, for 250 euros. It's a lucrative business - according to the police, a child can steal as many as five iPhones a day.

To put an end to this criminal network, 17 Romanian police officers have been assigned to France. They are specialised in fighting this type of trafficking.

We followed them during their investigation and at the police stations in Paris where Roma are arrested every day. This unique partnership between French and Romanian police aims to stamp out the criminal networks which have transformed the Roma children into money-making machines.