12.—(1) Subject to paragraph (2) and Article 13, the Commissioner may conduct an investigation into a complaint made by a child or young person—
(a)that his rights have been infringed by any action taken by a relevant authority; or
(b)that his interests have been adversely affected by any such action.
(2) The Commissioner shall not exercise his power under paragraph (1) in relation to a complaint unless he is satisfied that—
(a)the complaint raises a question of principle; and
(b)the complaint does not fall within an existing statutory complaints system.
(3) For the purposes of paragraph (2), a complaint falls within an existing statutory complaints system if a statutory provision confers power on a person to make the complaint to a body or person and—
(a)that body or person has power under a statutory provision to investigate the complaint; or
(b)that body or person would have power under a statutory provision to investigate the complaint but for some exclusion or restriction in that statutory provision.
(4) Where the Commissioner decides not to conduct an investigation into a complaint made under paragraph (1), he shall prepare a statement of his reasons for that decision and shall send a copy of the statement to—
(a)the complainant; and
(b)such other persons (if any) as the Commissioner considers appropriate.