Ind. Code § 33-26-7-3

Sec. 3. Discovery conducted under section 2 of this chapter is limited to production of documents from the administrative law judge presiding over the review under IC 6-1.1-15-3. The administrative law judge may not be summoned to testify before the tax court unless verified proof is offered to the tax court that the impartiality of the administrative law judge was compromised concerning the review.