375.400.  Investigation by director — duty of prosecuting attorney. — 1.  The director of the department of commerce and insurance shall, as often as he may deem proper, make careful inquiry and investigation as to the manner in which the money, funds or securities of insurance companies, doing business in this state, are invested or employed, and record the result of such inquiry or investigation in records kept in his office for the inspection of policyholders and public officials.

  2.  In the event of a violation of this section or of section 375.390, the prosecuting attorney of the proper county, or in the City of St. Louis, the circuit attorney, shall proceed at once by information or indictment against the offenders.