At the conclusion of the war, Becher was arrested and investigated at Nuremberg as a war criminal. Kasztner intervened on his behalf and sent an affidavit to his de-Nazification hearing, stating that "is cut from a different wood than the professional mass murderers of the political SS". It is possible that he did so with the knowledge of the Jewish Agency (Zionist leadership in Palestine, the Yishuv) in the hope of obtaining help in recovering stolen Jewish assets and capturing Eichmann in return. Kasztner later lied in court about having testified on Becher's behalf at Nuremberg trials, while he was asked about the affidavit. This defense of an SS officer angered the Jewish public as much as the original negotiations with Eichmann.