Ind. Code § 6-4.1-12-7
For the purpose of conducting an investigation described under section 6(3) or 6(6) of this chapter, the department of state revenue may:
(4) take testimony concerning any matter.
Each witness examined by the department is entitled to receive a fee equal to the same fee paid witnesses subpoenaed to appear before a court of record. The witness fee shall be paid in the same manner that erroneous tax payments are refunded under IC 6-4.1-10 .
As added by Acts 1976, P.L.18, SEC.1. Amended by P.L.79-2017, SEC.52.