(1) For reasons of unavailability or for other good cause shown, the testimony of any witness may be taken by deposition. Depositions may be taken orally or upon written interrogatories before any officer designated by the hearing officer and having power to administer oaths.

(2) Application. Any party desiring to take the deposition of a witness may make application in writing to the hearing officer, setting forth:

(3) Notice. Such notice as the hearing officer may order shall be given by the party taking the deposition to every other party.

(4) Taking and receiving in evidence. Each witness testifying upon deposition shall be sworn, and the parties not calling him shall have the right to cross-examine him. The questions propounded and the answers thereto, together with all objections made, shall be reduced to writing, read and subscribed by him, and certified by the officer before whom the deposition is taken. Thereafter, the officer shall forward two copies thereof, by registered mail to the hearing officer. Subject to such objections to the questions and answers as were noted at the time of taking the deposition and would be valid were the witness personally present and testifying, such deposition may be read and offered in evidence by any party. No part of a deposition shall be admitted in evidence unless there is a showing that the reasons for the taking of the deposition in the first instance exist at the time of the hearing.