Direction to investigate: Commission's prima facie finding triggers inquiry and mandates service of its order within seven days. When the Commission forms a prima facie view, the Secretary must convey its direction to the Director General to investigate within seven days, and that direction constitutes commencement of an inquiry under the Act; where the prima facie case pertains to contravention of prohibitions on agreements or abuse of dominance, the Secretary must also serve a copy of the Commission's order on the parties within the same seven day period.