(1) If a complaint is received in accordance with section 13 or information including the conclusion of analysis from the financial information unit in accordance with section 10, the head of the department shall conduct or conduct a preliminary investigation in relation to such complaint or information. Depending on the nature of the information, a subordinate officer may be appointed after giving appropriate time. (3) During the preliminary investigation, the investigating officer may exercise the same rights as the investigation officer under this Act.