For the purpose of this inquiry the board shall have all the powers of summoning before it and enforcing the attendance of witnesses, of administering oaths, and of requiring witnesses to give evidence, to produce books, papers, and other documents or things as the board may deem requisite to the full investigation of the matters into which it is inquiring, as are vested in the district court in civil cases.
Iowa Code § 679B.8
86 Acts, ch 1245, §944