323.In addition to the general power under section 167 to investigate the business of authorised persons and appointed representatives where there is “good reason” to do so, this section gives the Authority or the Secretary of State (“the investigating authority”) the power to appoint competent persons (who can be employees of the investigating authority) to conduct investigations where it appears that there are circumstances suggesting that some specific contravention or offence may have taken place.  The more specific grounds for the exercise of the powers under this section are reflected in the wider powers of the investigators (see notes on sections 171 to 173 below).
324.Among the contraventions that may be investigated by either the Authority or the Secretary of State under this section are a breach by an unauthorised person of the general prohibition, the commission of the misleading statements and practices offence under section 397, market abuse under section 118, or insider dealing under Part V of the Criminal Justice Act 1993. The Authority, but not the Secretary of State, may also launch an investigation under this section where a person is suspected of having committed an offence under prescribed money laundering regulations.
325.The Authority may also appoint investigators under this section to look into suspected contraventions of rules or regulations made under the Act, failures to comply with statements of principle made under section 64, or to investigate the fitness and properness of approved persons under Part V of the Act.  The fitness and properness of authorised persons may be investigated under section 167.
Commentary on Sections Part Xi: Information Gathering & Investigations Section 168: Appointment of persons to carry out investigations in particular cases