15.—(1) The Ombudsman may appoint in writing, either generally or in respect of any matter or event, such and so many members of the staff of the Ombudsman to be investigation officers for the purposes of all or any of the provisions of this Act and a person so appointed shall be referred to as an "investigation officer".

(2) Every investigation officer appointed under this section shall be furnished with a warrant of appointment as an investigation officer, and when exercising any power conferred on him or her by this section as an investigation officer, shall, if requested by a person affected, produce the warrant or a copy of it to that person.

(3) The Ombudsman may revoke an appointment made under subsection (1).

(4) An investigation officer may, for the purpose of obtaining any information which may be required in relation to the matter under investigation and in order to enable the Ombudsman to perform his or her functions under this Act, do any one or more of the following—

(a) at all reasonable times enter any premises, including, subject to regulations under section 9(5), a military installation, in which there are reasonable grounds to believe that any activity in connection with a complaint is or has been carried on or that books, records or other documents in relation to a complaint are kept and search and inspect the premises and any books, records or other documents on the premises,

(b) require a member of the Defence Forces or any other person to produce to the investigation officer any records and in the case of information that is kept in a non-legible form to reproduce it in a legible form or to give to him or her such information as the investigation officer may reasonably require in relation to any entries in such records,

(c) inspect and take copies of or extracts from any such records, file, papers or electronic information system in, at or on the place, including in the case of information in a non-legible form, copies of or extracts from such information in a permanent legible form,

(d) require any person to give to the investigation officer any information which the officer may reasonably require in relation to a preliminary examination or an investigation under this Act,

(e) require any person to give to the investigation officer such facilities and assistance within his or her control or responsibilities as are reasonably necessary to enable the investigation officer to exercise any of the powers conferred on him or her by or under this Act, and

(f) summon, at any reasonable time, any person to give to the investigation officer any information which he or she may reasonably require and to produce to the investigation officer any records which are in the power or control of that person.