On 4 August 1944, Silberbauer was ordered by his superior, SS-Obersturmführer (lieutenant) Julius Dettmann, to investigate a tip-off that Jews were being hidden in the upstairs rooms at Prinsengracht 263.
Pe 4 august 1944 Silberbauer a primit de la superiorul său, SS-Obersturmführer (locotenent) Julius Dettmann, ordinul de a investiga un pont că un grup de evrei se ascundeau în camerele de la etaj ale clădirii de pe Prinsengracht 263.