39.—(1) The Controller may, for the purpose of any inquiry under this Act, summon and examine witnesses on oath or affirmation, and may require the production of documents relevant to the inquiry.
(2) Any person summoned as a witness under subsection (1) who without reasonable excuse fails to attend at the time and place mentioned in the summons, or who, having attended, refuses to answer any question that may lawfully be put to him or to produce any document which it is in his power to produce, shall be guilty of an offence.