According to the "Sterbebücher" (death records) of Auschwitz, Jonas Fresco was murdered there on 11 October 1942. This date differs from the official date of death of 30 September 1942, as determined by the Dutch Ministry of Justice after the war. For the time being, the website joodsmonument.nl, list only the dates of death, as published at the time in the "Nederlandse Staatscourant" (Dutch Government Gazette) by the Ministry of Justice.
Sterbebuch Auschwitz (death record)
The official death certificate made out in Den Haag, nr. C2349 dated 15 September 1950 for Jonas Fresco. (scroll down and open line 4 of the present page 23).