[2] Opinions about his ghetto activities are controversial, though modern research concludes unanimously that he was an informer and collaborator motivated chiefly by personal interest.

[4][5] As a youth, he apprenticed as a journalist and editor in Łódź,[4] and eventually left Poland for Vienna, Austria, where he worked as a reporter on Jewish affairs for the Gerechtigkeit (Justice) periodical edited by Irena Harand.

[3][4][7] Gancwajch believed the Germans would win the war and called on Warsaw's Jews to serve them as a basic means of surviving.

[3][4][8] He was also a proponent of the Nazi Madagascar Plan to create an autonomous settlement for all Jews under the protection of the Third Reich in an overseas country.

[4] Adam Czerniaków, whom Gancwajch attempted to usurp as head of the Judenrat,[3][9] mentioned him in his diary as "a despicable, ugly creature".