23.—F65[(1) (a) Subject to the provisions of this section, where a complaint is made to the Commission under section 4 of the Act of 2001 or made or referred to it under section 22 or the Commission considers it appropriate to do so, the Commission shall carry out an investigation to determine whether, as appropriate—

(i) the person concerned or a connected person has done a specified act, or

(ii) the person concerned has contravened Part II, III or IV or the Act of 1997.

(b) Subject to the provisions of this section, where the Commission considers in the case of—

(i) a person who may have contravened Part II, III or IV or the Act of 1997 at a time when he or she was an office holder,

(ii) a person who is an office holder and who may have contravened Part II or the Act of 1997 before becoming an office holder,

(iii) a person to whom section 22(4)(b)(i) applies and who may have contravened Part IV, or

(iv) a person who may have done a specified act,

that it is appropriate to do so, it shall carry out an investigation to determine, whether, as may be appropriate—

(I) the person referred to in subparagraph (i) contravened Part II, III or IV or the Act of 1997 at a time when he or she was an office holder,

(II) the person referred to in subparagraph (ii) contravened Part II or the Act of 1997 before becoming an office holder,

(III) the person referred to in subparagraph (iii) contravened Part IV, or

(IV) the person referred to in subparagraph (iv) did a specified act.

(1A) The Commission shall not carry out an investigation under subsection (1) into a complaint under subsection (1) of section 4 of the Act of 2001 in relation to a matter referred to in paragraph (a) of that subsection unless—

(a) the complaint was made or referred to it by a Committee, or

(b) the Commission becomes of opinion, after consideration by it of any report of an inquiry officer in relation to the matter and any statements or documents accompanying the report, that there is sufficient evidence to establish a prima facie case in relation to the alleged specified act concerned and that, if it was in fact done, it is an act falling within the said paragraph (a).

(1B) The Commission shall not investigate a complaint by a person other than a member or a person referred to in paragraph (c) or (d) of section 22(4) if it considers the complaint to be frivolous or vexatious.

(1C) Subject to subsection (1A)(b), if the Commission becomes of opinion that evidence sufficient to sustain a complaint referred or made to it under section 22 or section 4 of the Act of 2001 is not and will not be available, it may decide not to carry out, or to discontinue, an investigation under this section and, if it does so, it shall prepare a record of the decision and subsection (1) and (4) of section 24 shall apply in relation to such a record as it applies to a report under subsection (1) of that section with any necessary modifications.]

(2) Before the Commission decides whether to carry out under subsection (1) an investigation of a matter that—

(a) relates to a person who holds or held a designated directorship of, or occupies or occupied a designated position in, a public body, and

(b) was not the subject of a complaint referred or made to it under section 22,

the Commission shall—

(i) consult with any Minister of the Government on whom a function in relation to the body stands conferred, and

(ii) give to any such Minister of the Government as aforesaid and to the body a statement in writing of the reasons why it considers it appropriate that the investigation should be carried out,

and it shall decide not to carry out the investigation unless, having considered any representations made to it by that Minister of the Government or the body, it is satisfied that it is appropriate to carry it out and that an adequate investigation cannot or will not be carried out by or on behalf of that Minister of the Government or the body or any other authority.

(3) Where the Commission, either during or at the conclusion of an investigation under this section, becomes of opinion that the person the subject of the investigation has not contravened F66[the provision of this Act or the Act of 1997 to which the investigation relates or has not done a specified act, but, as may be appropriate, may have contravened another provision of Part II, III or IV or the Act of 1997 or may have done a specified act, it may carry out an investigation under this section to determine, as appropriate, whether the person has contravened that other provision or that Act or has done a specified act].