(1) The department shall make rules and regulations, which shall have the force and effect of law, to govern reports and accounts by all persons dealing in or handling fuel for the purpose of enabling the department to ascertain whether or not any fuels are being dealt with, handled, or stored in this state under such circumstances as to become liable to the tax imposed by any law relating to a tax on fuel.
(2) The department is further given power to investigate, or cause to be investigated under its authority, all cases involving dealing in fuel by persons receiving, handling, or storing the same and to determine from such investigation whether or not any section in this chapter relating to the fuel tax is being evaded or illegally avoided. The determination of the department in any case shall be prima facie valid and authentic in all courts in this state and in all actions involving the validating of taxes on persons subject to the provisions of part I or part II of this chapter.
(3) The department may investigate and audit inventories, receipts, and disposals of fuel to ascertain the validity of all taxes collected and remitted to the department. Any fuel which cannot be accounted for, except for normal temperature gains, by a terminal supplier, importer, exporter, blender, or wholesaler is subject to all taxes levied under this chapter. As used in this subsection, “normal temperature gains” shall be limited to 1.5 percent of the total disposals in any month, unless the terminal supplier, importer, exporter, blender, or wholesaler demonstrates to the reasonable satisfaction of the department that temperature gains occurred in excess of 1.5 percent of total disposals for the month.
(4) The department may assess and collect any tax, penalty, or interest against any person who purchases, receives, or disposes of motor fuel in violation of any provision of this part.