Section 28 of the Principal Act is amended by inserting the following subsections after subsection (5):
"(5A) Where -
(a) a request under section 7 relates to a record to which subsection (1) applies but to which subsections (2) and (5) do not apply or would not, if the record existed, apply, and
(b) in the opinion of the head concerned the disclosure of the existence or non-existence of the record would have the effect specified in subsection (1),
he or she shall refuse to grant the request and shall not disclose to the requester concerned whether or not the record exists.
(5B) Notwithstanding paragraph (a) of subsection (2), a head shall, subject to paragraphs (b) to (e) of that subsection and subsections (5) and (6), refuse to grant a request under section 7 if, in the opinion of the head, access to the record concerned would, in addition to involving the disclosure of personal information relating to the requester, also involve the disclosure of personal information relating t