In 1943, the British created this propaganda forgery depicting Hans Frank, the Governor-General of the Polish Generalgouvernement.
The stamp design is an imitation of the 1941 Generalgouvernement 20 Groschen Hitler Issue, MiNr. 77. It exists perforated ("A" suffix) and imperforate ("B" suffix).
The stamps were airdropped to the Polish Resistance in January-April 1943. The Resistance mailed a small quantity of covers, each containing a propaganda leaflet, bearing the stamp and two genuine 2-Groschen stamps to various addresses in Occupied Poland.
For more on this issue, see Propaganda and Espionage Philately, by SGM Herbert A. Friedman (Ret.).