Vulnerable young people are more at risk of being exploited by criminals than authorities realise, according to a survey of around 500 frontline professionals in Rotterdam.

The study by the anti-human trafficking centre CKM said the official figures masked the scale of the problem, according to neighbourhood police officers, youth workers and school attendance monitors.

Nearly half of those interviewed said they had been in contact with at least one person who had been exploited by criminals, and the problem appeared to be growing. Young people with learning difficulties or insecure family situations were most at risk.

‘There is a huge gap between the official figures and what professionals who work with this group of young people see,’ said CKM spokesman Shamir Ceuleers.

He said criminals typically approached their victims on the street, at locations where teenagers congregate, at school or via social media, and ask them to act as couriers or drug runners.

‘They’re asked to do a job in exchange for free dope,’ he said. ‘Once they get tangled up in it, they can’t get out.

‘These young people don’t see themselves as victims. But they know they’re involved in crime so they don’t go straight to the police.’

The CKM said community workers should be trained to spot the early signals of exploitation. A nationwide study is also planned based on the findings in Rotterdam.