453B.10  Confidential nature of information.
  Notwithstanding any law to the contrary, the director or an employee of the department shall not reveal any information obtained from a dealer; nor shall information obtained from a dealer be used against the dealer in any criminal proceeding, unless the information is independently obtained, except in connection with a proceeding involving taxes due under this chapter from the dealer against whom the tax was assessed.
  A person who violates this section is guilty of a simple misdemeanor.
  This section does not prohibit the director from publishing statistics that do not disclose the identity of the dealers.
  A stamp, label, or other official indicia denoting payment of the tax imposed under this chapter shall not be used against a taxpayer in a criminal proceeding, except that such information may be used against the taxpayer in connection with the administration or civil or criminal enforcement of the tax imposed under this chapter or any similar tax imposed by another state or local unit of government.
90 Acts, ch 1251, §46
C91, §421A.10
C93, §453B.10