Menachem Birnbaum (born 1893 in Vienna, died probably 1944), was an Austrian Jewish book illustrator and portrait painter.
Birnbaum married Ernestine (Tina) Esther Helfmann, with whom he had two children: Rafael Zwi and Hana.
In the spring of 1943 he was arrested by the Gestapo along with his relatives and transported on 10 March 1943 to a Nazi concentration camp, presumably Auschwitz.
Menachem was seen alive and spoken to in Auschwitz in October 1944 by a Dutch Jewish survivor, who told about it to his brother Uriel Birnbaum in Holland after WW2.
This would mean that the theory of him dying in March 1943 in the Sobibor extermination camp is incorrect, a theory based solely on an unconfirmed assumption by the Red Cross that the trains from the German holding camp at Westerbork, Holland were sent to Sobibor on the day of his arrest and deportation.