Leopold Trepper (February 23, 1904 – January 19, 1982) was a Polish Communist, agent of the Red Army Intelligence, with the code name of Otto and had been working with them since 1930.
He was the technical director of intelligence agency in western Europe and was responsible for recruiting agents and creating espionage networks.
He was also a resistance fighter and journalist of Jewish descent.
Trepper was an experienced intelligence officer, an extremely resourceful and capable man who was completely at home in the west, a man who could not be drawn in conversation, who lived a concealed life and whose special talent was a keen judge of people that enabled him to penetrate significant groups with ease.
By the start of World War II, Trepper controlled a large espionage network in Belgium and seven espionage networks in France.