In some of the versions there is mentioning of a concentration camp in Chisinau, but as far as I know there never was such a camp, which raises the question if this story is real or just a legend.
This is the version you can find on Wiki:
Eliahu Itzkovitz was a Romanian Jew who during the Second World War, while a prisoner in a concentration camp witnessed the murder of his family at the hands of a Romanian prison guard named Stănescu. Itzkovitz vowed to avenge his family's murder at the hands of his fellow Romanian, but was unable to find to the man after the war. After the war he subsequently immigrated to Israel where he served in the Israeli Defense Forces until he learned that Stănescu had enlisted in the French Foreign Legion which led him to desert from the IDF and join the Foreign Legion. Itkowitz was able to track down and kill Stănescu in French Indochina. He was later court-martialed in Israel for desertion and sentenced to one year in prison.