In Auschwitz, Victor befriended another Dutch Jew who was about the same age and had been deported from the Netherlands just a few weeks after Victor.
Victor's friend survived the war and reported to Dutch authorities in 1947 that he had witnessed Victor's death in October 1944: Victor had been shot while attempting to escape.
The friend did not report which camp the two men in were at the time, but after tracing the survivor's wartime path, it appears that the boys were still in Auschwitz at the time of Victor's death.
Thus, Victor's official fate is that he was shot in October 1944 in Auschwitz. It is unclear if it was related to the rebellion, but it seems very possible; survivors have reported that no one actually tried to escape from Auschwitz under normal circumstances, because it was seen as impossible, which Victor would have known as he had been in Auschwitz for almost a year at the time of his death.
Victor may have been among the 200 prisoners shot in retaliation for the rebellion, among the 250 killed during the rebellion, or he may have tried to escape during the chaos surrounding the rebellion and was unsuccessful.
Alternatively, Victor's death may have been entirely unrelated to the rebellion.