Sadegh Tabatabai brother in law of Ahmad Khomeini and son in law of Lebanese Imam Mous Sadr teach Iranians how to vote in the referendum of Islamic Republic on 30 March 1979 . Tabatabaei get wealthy in the Islamic Republic and was arrested in 1983 for transportation of opium in his suitcase . The German court ruled that because of his diplomatic position , he was immune to be prosecuted in German courts .