In 1920 Mohammad Taqi returned to Iran and joined the Gendarmerie. In June 1920 he was promoted to the rank of colonel and in September 1920 he became commander of Gendarmerie of Khorasan. On 3 April 1921 in a military coup with his small force of only 200 gendarmes, he had Ahmad Qavam, the Governor-general of Khorasan, arrested and sent him to capital where he was imprisoned. He then became head of the provincial Autonomous Government of Khorasan. In June, Ahmad Qavam was released from prison and became Premier of homeland.