(a) The department may make an investigation of property on which a return has been filed or of taxable property upon which no return has been filed. In either case, the department may make its own valuation of the taxable property, which is prima facie evidence of full and true value.
(b) An employee or agent of the department may enter any premise necessary for the investigation during reasonable hours and may examine property and appropriate records. The owner of the taxable property upon request shall furnish to the employee or agent of the department reasonable assistance required for the investigation. If refused entry, the department may seek a court order to compel entry.
(c) For the purpose of the investigation the owner of the taxable property or a representative of the owner may be required to appear for examination under oath by the department.