Notwithstanding anything contained in any legal provisions in terms of which a witness shall not be compellable or permitted to give evidence in respect of certain matters on grounds of public policy or from regard to public interest, it shall be competent for any person in any civil proceedings to adduce evidence of any communication alleging the commission of an offence, if the making of that communication prima facie constitutes an offence, and it shall be competent for the person presiding at such proceedings to determine whether the making of such communication prima facie does or does not constitute an offence, and such determination shall, for the purposes of those proceedings, be final.