Now, because of a newly opened Nazi archive, the mystery has been resolved.
Bar-Yuda, now 74, was one of the first to obtain Nazi documents now available to the public after they were stashed away for more than 60 years in a secret German archive containing the largest registry of Holocaust victims ever. Up to now, only limited queries were answered.
The archive proved that Bar-Yuda's father, Alfred Kastner, was killed in a Nazi gas chamber at the Majdanek death camp in Poland. Bar-Yuda said despite the tragic ending, he was grateful to finally have some closure and an exact date to recite Kaddish, the Jewish prayer for the dead.