(1)  Where the Magistrate directs a local investigation by any person under section 139, the Magistrate may—

   (a)  furnish such person with such written instructions as may seem necessary for his guidance;

   (b)  declare by whom the whole or any part of the necessary expenses of the local investigation shall be paid.

   (2)  The report of such person may be read as evidence in the case.

   (3)  Where the Magistrate summons and examines an expert under section 139, the Magistrate may direct by whom the costs of such summoning and examination shall be paid.