The family may be known at the national archives at The Hague and the files might be found in their central archive Special Justice (Nationaal Archief Centraal Archief Bijzondere Rechtspleging). Be aware that these files cannot be accessed online and no photocopies can be obtained. You may use a mobile phone or make notes. Because of corona there is only limited access for single persons. Ron Peeters(NL)
