339.This section enables the Authority or an investigator appointed by either the Authority or the Secretary of State under this Part to compel the production of a document by a person who is holding a document on behalf of another person if they would have the power to compel the latter to produce the document if they held it.  If any person required to produce a document fails to do so, they may be compelled to state where, to the best of their knowledge, the document is.
340.A document once obtained may be copied or have extracts taken from it, and the person producing the document, or any other relevant person, may be required to explain it.  But the production of a document does not affect any rights a third party may have over it.
341.Documents subject to banking confidentiality may also be withheld unless the person holding the information, or the person to whom the duty of confidence is owed, is the person under investigation or a related company, or the person to whom the duty is owed consents to its disclosure, or the requirement to disclose has been specifically authorised by the Authority or the Secretary of State.
Commentary on Sections Part Xi: Information Gathering & Investigations Section 175: Information and documents: supplemental provisions