Subsections (2) to (4) apply if an investigator considers that any person ("A") is or may be able to give information which is or may be relevant to the investigation.
The investigator may require A—
to attend before him at a specified time and place and answer questions; or
otherwise to provide such information as he may require for the purposes of the investigation.
The investigator may also require A to produce at a specified time and place any specified documents or documents of a specified description which appear to the investigator to relate to any matter relevant to the investigation.
The investigator may also otherwise require A to give him all assistance in connection with the investigation which A is reasonably able to give.
"Investigator" means a person appointed under subsection (3) of section 168 (as a result of subsection (2) of that section).