Finance ministry investigators say there has been an increase in money laundering operations in sectors which employ large numbers of low-skilled foreign workers, such as healthcare, farming and delivery services.

The money is laundered via contractors and sub-contractors who pay their workers in cash earned via crime while billing their clients in the normal way.

The cash is “bought” from criminals and “compensated” by means of fake bank payments to companies led by criminals who then spend the laundered money buying houses and other goods and financing other criminal activities.

The method is becoming widespread and leads to unfair competition, tax dodging and the abuse of foreign workers, chief public prosecutor Michiel Zwinkels told the NRC.

“The worry is that criminal money is penetrating deep into the economy, ” he told the paper.

Last year, a court in Rotterdam sentenced for people to prison sentences of up to five years for laundering €4.5 million.

The case is the tip of the iceberg, Zwinkels said. “It shows that reporting small unusual transactions is important despite criticism from the banks. If banks were not under this obligation, we would never have uncovered this type of fraud,” he said.

Zwinkels called on the government to improve collaboration between different government bodies to tackle money laundering, for instance by circumventing privacy rules when it comes to sharing privileged information, such as court rulings.

If someone who has been convicted of fraud requests a licence to build temporary homes, the local council in question would not have access to the whole verdict because of privacy restrictions, Zwinkels said.

“We should take a leaf out of Italy’s book. There all government departments have a duty to tackle the mafia. If we had the same system in this country, the public prosecution office could share much more information with local authorities than we do now. And that would help us enormously in combatting money laundering,” he said.