Suits for collection of unpaid taxes.

(1) Upon demand of the department, the Department of Legal Affairs or any state attorney of any judicial circuit shall bring appropriate actions in the name of the state, or in the name of the Department of Revenue in the capacity of its office, for the recovery of the above-mentioned taxes, penalties, and interest, and judgment shall be rendered for the amount so found to be due together with costs. However, if it shall be found as a fact that such failure to pay was willful on the part of any terminal supplier, importer, exporter, or wholesaler, judgment shall be rendered for double the amount of the tax found to be due with costs. The department may employ an attorney at law to institute and prosecute proper proceedings to enforce payment of the fuel taxes provided for by the laws of this state and the penalties and interest provided for by part I or part II of this chapter and to fix the compensation for the services of said attorney at law.

(2) Any seller and purchaser convicted of conspiring to defraud the state of any tax imposed under this chapter may be held liable for the tax and any penalty and interest due on such tax.