In addition, a Jokos file (number 60740) on this person is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.
A recently found document indicates that Mauritz de Vries never reached Auschwitz. He died in the train bound for Auschwitz and was probably thrown out of the train. His body was found near the station in Ehrenforst.
The official date of death, specified in his death certificate is 18 November 1942.