4. Whether publication objectionable a matter of expert judgment---(1)
 The question whether or not a publication is objectionable is a matter
 for the expert judgment of the person or body authorised or required, by
 or pursuant to this Act, to determine it, and evidence as to, or proof
 of, any of the matters or particulars that the person or body is
 required to consider in determining that question is not essential to
 its determination.

   (2) Without limiting subsection (1) of this section, where evidence as
 to, or proof of, any such matters or particulars is available to the
 body or person concerned, that body or person shall take that evidence
 or proof into consideration.