(1)For the purposes of an investigation a Commissioner may require any officer or member of the health service body concerned or any other person who in his opinion is able to supply information or produce documents relevant to the investigation to supply any such information or produce any such document.

(2)For the purposes of an investigation a Commissioner shall have the same powers as the Court in respect of—

(a)the attendance and examination of witnesses (including the administration of oaths and affirmations and the examination of witnesses abroad), and

(b)the production of documents.

(3)No obligation to maintain secrecy or other restriction on the disclosure of information obtained by or supplied to persons in Her Majesty’s service, whether imposed by any enactment or by any rule of law, shall apply to the disclosure of information for the purposes of an investigation.

(4)The Crown shall not be entitled in relation to an investigation to any such privilege in respect of the production of documents or the giving of evidence as is allowed by law in legal proceedings.

(5)No person shall be required or authorised by this Act—

(a)to supply any information or answer any question relating to proceedings of the Cabinet or of any Committee of the Cabinet, or

(b)to produce so much of any document as relates to such proceedings;

and for the purposes of this subsection a certificate issued by the Secretary of the Cabinet with the approval of the Prime Minister and certifying that any information, question, document or part of a document relates to such proceedings shall be conclusive.

(6)Subject to subsections (3) and (4), no person shall be compelled for the purposes of an investigation to give any evidence or produce any document which he could not be compelled to give or produce in civil proceedings before the Court.