Few cases of focusing on criminal exploitation or the exploitation of workers ever come to court and of those that do, only around half result in a conviction, the government’s human trafficking and exploitation rapporteur said on Thursday in a new report.

Between 2013 and 2017 an average of 23 cases involving working arrangements or other forms of exploitation, such as forced begging, went to court, the report says. This is well below the number of cases involving human trafficking and sexual exploitation.

The victims of this form of trade in humans are often migrants, don’t speak the language and do not know their rights,’ rapporteur Herman Bolhaar said. He said more cases should be taken to court in order to build up a better picture of what is permissible and what is illegal when it comes to exploitation at work.