Dutch health and youth service inspectors say they have evidence that fake certificates of good behaviour (VOG) are in circulation after finding nine people working in youth social services with forged documents.
The nine people worked for a staffing agency, which alerted officials to the problem last week.
They have been suspended and the matter reported to the police. It is unclear from the inspectorate statement if the workers had direct contact with youngsters or what work they were doing.
The inspectorate says it suspects more VOG certificates may be in circulation and is urging hospitals, youth social service departments and staffing agencies to make sure they have original documents for all staff in their possession.
The nine forged certificates were all pdfs which did not have the requisite water marks and other security symbols.
VOG certificates are required by law for people working with children. The inspectorate said it would step up its own checks in the coming months.