334.618.  Investigation and filing of complaints for violations. — Upon receiving information that any provision of sections 334.500 to 334.687 has been or is being violated, the executive director of the board or other person designated by the board shall investigate and, upon probable cause appearing, the executive director shall, under the direction of the board, file a complaint with the administrative hearing commission or appropriate official or court.  All such complaints shall be handled as provided by rule promulgated under section 324.002.