 In April and May 1943, he wrote three reports to SS-Obersturmführer Heinz Röthke in which he denounced the hiding of foreign Jewish children by friends of Juliette Stern within the Union Générale des Israélites de France (UGIF).As Charles du Paty de Clam, Commissioner-General for Jewish Affair, was accused of passivity and disinterest towards the aryanisation process, Joseph Antignac replaced him on 17 May 1944.Joseph Antignac tried to make all documents related to the organization disappear in August 1944 as the Allies were heading to Paris.