The department may employ auditors or other persons to audit and examine the books and records of a permit holder or other person dealing in tobacco products to ascertain whether the permit holder or other person has paid the amount of the taxes required to be paid by the permit holder or other person under the provisions of this chapter. If the taxes have not been paid, as required, the department shall assess against the permit holder or other person, as additional penalty, the reasonable expenses and costs of the investigation and audit.