1. If an evidentiary hearing is required, the judge or justice may direct that the record be expanded by the parties by the inclusion of additional materials relevant to the determination of the merits of the petition.
2. The expanded record may include, without limitation, letters which predate the filing of the petition in the district court, documents, exhibits and answers under oath to written interrogatories propounded by the judge. Affidavits may be submitted and considered as a part of the record.
3. In any case in which the record is expanded, copies of proposed letters, documents, exhibits and affidavits must be submitted to the party against whom they are to be offered, and the party must be afforded an opportunity to admit or deny their correctness.
4. The court must require the authentication of any material submitted pursuant to subsection 2 or 3.