Five men and two women have been arrested for their role in a scam which involved sending fake bills for advertising to companies and private individuals.

The gang is said to have netted at least €400,000 from the con. In total, 34 victims made formal complaints to the police but investigators think at least 140 people lost money.

The gang sent fake bills to companies and put pressure on them to pay. If they refused, they were sent a copy of a fake order form signed by one of their own workers.

The signatures had been copied from other documents, police said in a statement, adding that it is unclear how the gang got hold of those papers. Once confronted with the signed order, the victims almost always agreed to settle.

One victim, a woman from Rotterdam, lost around €100,000 through the con, police said.