Edited sentence: According to Kovner's own account, Chaim Weizmann approved the idea and put him in touch with the scientist Ernst Bergmann, who gave the job of preparing poison to Ephraim Katzir (later president of Israel) and his brother Aharon.As Kovner and an accomplice were returning to Europe on a British ship, they threw the poison overboard when Kovner was arrested.At the end of World War II, Lithuanian Jew Abba Kovner was one of the founders of a secret organization Nakam (revenge), also known as Dam Yisrael Noter ("the blood of Israel avenges", with the acronym DIN meaning "judgement") whose purpose was to seek revenge for the Holocaust.He was imprisoned for a few months in Cairo and Plan A was abandoned, meaning no well poisoning had actually occurred.Historians have expressed doubt over Weizmann's involvement, since he was overseas at the time Kovner specified.In pursuit of Plan A, members of the group were infiltrated into water and sewage plants in several cities, while Kovner went to Palestine in search of a suitable poison.Kovner discussed Nakam with Yishuv leaders, though it is not clear how much he told them and he doesn't seem to have received much support.Plan A was to kill a large number of German citizens by poisoning the water supplies of Hamburg, Frankfurt, Munich, and Nuremberg.Plan B was to kill SS prisoners held in Allied POW camps.The Katzir brothers confirmed that they gave poison to Kovner, but said that he only mentioned Plan B and they denied that Weizmann could be involved.Two plans were formulated