International organizations — United Nations — Officials — Immunity — Scope — Convention on the Privileges and Immunities of the United Nations, 1946, Article VI, Section 22 — Diplomatic Privileges (United Nations and International Court of Justice) Order 1949, Article 12 — Defamation proceedings — United Nations Special Rapporteur — Whether immune from suit — Whether alleged defamatory statements made in capacity as Special Rapporteur — Whether certificates issued by Secretary-General of United Nations and Minister of Foreign Affairs conclusive evidence of defendant’s immunity — Role of national courts in questions of immunity

Relationship of international law and municipal law — Treaties — Immunity arising under treaty — Duty of national courts and executive — The law of Malaysia