The master may prescribe the form for submission of accounts which are in issue. In any proper case the master may require or receive in evidence the statement of a certified public accountant who testifies as a witness. If any item submitted or stated is objected to, or shown insufficient in form, the master may require that a different form be furnished, or that the accounts or any item thereof be proved by oral testimony or written interrogatories of the accounting parties, or in such other manner as the master directs.
Iowa. R. Civ. P. 1.940