(1) This section sets out the grounds on which access may be refused.
(2) It is the Parliament's intention that—
(a) the grounds are to be interpreted narrowly; and
(b) an agency or Minister may give access to a document even if a ground on which access may be refused applies.
(3) On an application, an agency may refuse access to a document of the agency and a Minister may refuse access to a document of the Minister—
…
(b) to the extent the document comprises information the disclosure of which would, on balance, be contrary to the public interest under section 49