Notwithstanding the provisions contained in section 9 of this Act, the appropriate Government may disclose the following information, namely:--
         (a) information supplied by informant in respect of which disclosure is consented to in writing by the informant or by any person authorised by the said informant;
         (b) information otherwise available to the public under any Act or as a public document;
         (c) information in the form of an index or list of the names and addresses of informants together with the classification, if any, allotted to them and the number of persons engaged.