(a) A deposition may be returned to the state agency before which the contested case is pending by mail or by a party interested in taking the deposition or another person.
(b) For a deposition returned by mail, the state agency shall:
(1) endorse on the deposition the fact that it was received from the post office; and
(2) have it signed by the agency employee receiving the deposition.
(c) For a deposition returned by means other than mail, the person delivering it to the state agency shall execute an affidavit before the agency stating that:
(1) the person received it from the hands of the officer before whom it was taken;
(2) it has not been out of the person's possession since the person received it; and
(3) it has not been altered.