(a) At no stage of the proceeding following the issuance of a notice of hearing and prior to the issuance of the Secretary's decision thereon shall an employee of the Department who is or may reasonably be expected to be involved in the decision process of the proceeding discuss ex parte the merits of the proceeding with any person having an interest in the proceeding or with any representative of such person: Except that procedural matters and status reports shall not be included within the limitation: And except further that an employee of the Department who is or may reasonably be expected to be involved in the decisional process of the proceeding may discuss the merits of the proceeding with such a person if all parties known to be interested in the proceeding have been given notice and an opportunity to participate. A memorandum of any such discussion shall be included in the record of the proceeding.

(b) No person interested in the proceeding shall make or knowingly cause to be made to an employee of the Department who is or may reasonably be expected to be involved in the decisional process of the proceeding an ex parte communication relevant to the merits of the proceeding except as provided in paragraph (a) of this section.

(c) If an employee of the Department who is or may reasonably be expected to be involved in the decisional process of the proceeding receives or makes a communication prohibited by this section, the Department shall place on the public record of the proceeding:

(1) All such written communications;

(2) Memoranda stating the substance of all such oral communications; and

(3) All written responses, and memoranda, stating the substance of all oral responses thereto.

(d) Upon receipt of a communication knowingly made or knowingly caused to be made by a party in violation of this section, the Department may, to the extent consistent with the interest of justice and the policy of the underlying statute, take whatever steps are deemed necessary to nullify the effect of such communication.

(e) For the purposes of this section, ex parte communication means any oral or written communication not on the public record with respect to which reasonable prior notice to all interested parties is not given, but which shall not include requests for status reports (including requests on procedural matters) on a proceeding.