(1) If the motion is not dismissed summarily, the judge 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 motion.
(2) The expanded record may include, without limitation, letters predating the filing of the motion in the court, documents, exhibits and answers under oath, if so directed, 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 an expanded record is directed, copies of the letters, documents, exhibits and affidavits proposed to be included shall be submitted to the party against whom they are to be offered, and he shall be afforded an opportunity to admit or deny their correctness.
(4) The court may require the authentication of any material under subsection (1) or (2) of this section.