In any proceedings under this Part, the court determining the
proceedings—
(a)
must, on the application of the Commissioner, take steps to maintain the
confidentiality of information classified by the Commissioner as criminal
intelligence, including steps to receive evidence and hear argument about the
information in private in the absence of the parties to the proceedings and
their representatives; and
(b) may
take evidence consisting of, or relating to, information that is so classified
by the Commissioner by way of affidavit of a police officer of or above the
rank of superintendent.