Research into the wartime civil registries of one of the civil registry offices in Upper Silesias (Poland) discovered many records that corresponded to deaths of inmates from the "Reichsautobahnlager Annaburg" and "Zwangsarbeitslager Niederkirch" camps.
A certificate of death for Abraham Assou as discovered there, stated that he died on 7 December 1942 in Camp Annaberg. In it was mentioned an official cause of death as general body weakness (allgemeine Körperschwäche).
The archives of the Jewish Council of Amsterdam list Abraham Assou being deported from Camp Westerbork "eastward" on 11 October 1942.
Private collection of Edward Haduch, Kedzierzyn-Kozle (Poland), the official death certificate of Abraham Assou, issued by German authorities (Standesamt) of Annaberg and the Archive of the Jewish Council of Amsterdam.
However, by establishing the date of death of Abraham Assou, the official date is maintained as stated after the war by the Dutch Department of Justice.