330.Where an investigation has been launched into a person under section 167 or 168, the Authority or the Secretary of State (whichever is the investigating authority) must notify that person that the investigator has been appointed..  They must also inform the person under investigation of the reason for the appointment, and the particular provisions of the Act under which the appointment has been made.
331.However no notification is needed for investigations under section 168 into possible insider dealing, market abuse or misleading statements and practices, or into contraventions of the general prohibition under section 19, the financial promotion prohibition under section 21 or the prohibition on promoting collective investment schemes under section 238, since in those cases the investigator may not know the identity of the perpetrator or may be looking into market circumstances at the outset of the investigation rather than investigating a particular person.  Nor is notification required if the investigating authority believes that it would be likely to result in the investigation being frustrated.
332.Subsection (5) allows employees of the investigating authority to act as investigators under this Part of the Act.
333.Subsections (7) and (8) allow the investigating authority to control the scope, timetable and form of the investigation by issuing directions to the investigator(s).  Any directions must be notified to the person under investigation under subsection (9) except for those types of investigation where initial notice is not required, or where the investigating authority believes that notification would be likely to result in the investigation being frustrated.
Commentary on Sections Part Xi: Information Gathering & Investigations Section 170: Investigations: general