Procedure as to letters: Postal authorities must deliver requested documents when senior magistrate or court directs. A District Magistrate, Chief Judicial Magistrate, Court of Session or High Court may require a postal authority to deliver any document, parcel or thing in its custody required for investigation, inquiry, trial or other proceeding under the Sanhita; other Magistrates, Commissioners of Police or District Superintendents of Police may require the postal authority to search for and detain such items pending the order of a District Magistrate, Chief Judicial Magistrate or Court under the primary power.