Police and tax office investigators have arrested six men in Arnhem for defrauding at least 170 companies by posing as tax office officials.

In total the suspects, who are aged 20 to 39, are thought to have conned their victims out of €2.2m.

They worked the con by phoning companies to say that they had either unpaid tax bills or outstanding fines and threatened their victims with sequestration orders unless they paid over the funds into a named account immediately.

The funds were paid into accounts owned by middlemen who allowed the criminals to use their bank accounts and pin cards, sometimes after violent threats were made against them, the tax office statement said.

The conmen then withdrew the cash from those accounts, often while the phone conversation was still taking place.

The tax office said 30 of these middle men will be arrested in the coming days while a further 200 will be invited to give a statement.

During the raids on five properties in Arnhem officials seized various documents, 500 euro notes, bank passes and a script detailing how to carry out phone conversation.