Isaac Wurms was arrested at the so-called CPN-Aktion. After the German invasion of the Soviet Union, more than 400 prominent communists were arrested on the night of 24 to 25 June 1941 and another 175 people in the following months. These arrests were made by the Dutch police, on behalf of the German Sicherheitspolizei. The information about the arrested communists had often been collected before the war by the German intelligence services, in collaboration with their Dutch colleagues.
The detainees were interned in camp Schoorl. About 200 of them were released soon after, after it was shown that they were no longer involved with the CPN (Communist Party Netherlands). The rest ended up in camp Amersfoort, from where most were transported to Germany. In the end, about 250 detainees died in German concentration camps.
The archives of the Generalkommissariat für das Sicherheitswesen (archive 077) contain various documents relating to German involvement with Communism and Marxism. This includes documents related to the CPN Aktion. Inventory number 1218 contains documents concerning the possible transfer of 100 CPN officials imprisoned in Schoorl and Amersfoort to a German concentration camp in connection with expected demonstrations on Queen's Day, 1941-1942. In a telex message from the SD (dated 30-8-1941) 75 prisoners are mentioned who were held in camp Schoorl at that time. Below Isaac Wurms. All were selected for a transport “…in ein K.Z. nach Deutchland”.
On the basis of this report it can be concluded that Isaac Wurms was in Schoorl and would be deported from there to Germany. A later message, which can be found in the same file, indicates that the expected protests during Queen's Day failed to materialize and, as a result, the transports to Germany did not take place. When Isaac Wurms was still transported and where to is not entirely clear.
In the German criminal file (1943) against the group “Nederlandse Volksmilitie” (Dutch Peoples Militia), the name Isaac Wurms is mentioned a few times as one of the contacts (archive 077, inventory number 1196d). It cannot be ruled out that his name was mentioned by the detainees during interrogations, because it was already known that he had died in Neuengamme
Source: NIOD institute/Hubert Berkhout. (the mentioned dossiers are to see and to consult in the reading room of the NIOD intstitute)