Hillel Katz

On 13 September 1943, Trepper escaped Gestapo custody under watch while visiting a pharmacy. After Trepper escaped, Katz was taken to the Rue des Sausasaies in Paris and tortured to determine if he knew anything of the escape plan, but he never betrayed Trepper. After Trepper's escape, Katz disappeared. It is not known what happened to him but he was likely tried at a Luftwaffe court martial, presided over by Judge Advocate Manfred Roeder and then either likely shot or deported to a concentration camp, as happened to many other people associated with the Red Orchestra in France.

On 25 November 1942, Trepper was arrested by Gestapo officer Karl Giering and immediately offered to collaborate with the Abwehr. In December 1942, Hillel Katz was arrested.

In September 1939, Katz enlisted in the French Foreign Legion. He was captured and taken prisoner in June 1940 during the German advance, but managed to escape with Aldred Corbin by swimming across the River Somme. After his escape, Katz started to use the alias André Dubois. Corbin would become a chicken breeder and inventor of poultry feed. Katz would later recruit him for the Trepper group, to store a radio transmitter in Giverny where his poultry farm was located. Corbin would later become the commercial director of Simex.

During the late 1930s, Katz lived at 13 Quai Saint-Michel in Paris, where he was a member of the communist section of the 5th arrondissement of Paris. During that period, Katz worked in a Racine bookshop where he managed the Youth fund. The book shop was popular with militants and political refugees.

Hillel Katz (born 24 September 1905 in Cieszyn, Austro-Hungarian Empire) was a Polish Jewish Communist, who was an important member of a Soviet espionage network in occupied France, that the German Abwehr intelligence service later called the "Red Orchestra" ("Rote Kapelle"). In the role of an underground executive and recruiter, he acted as both secretary and assistant to Leopold Trepper and liaised between Léon Grossvogel and Henry Robinson in matters relating to the running of the French covert black market trading company Simex. Katz had a number of aliases that he used to disguise his identity, including Andre Dubois, Rene and Le Petite Andre.