Gujarat High Court Criminal Manual (subordinate court practice), 1977
Whenever a Medical Officer is questioned about the result of his examination of any person, corpse or substance, evidence should always be taken to prove that the person, corpse or substance examined by him and to the examination of which he testifies, is the person, corpse or substance in question in the case. For this purpose the evidence of the person who conveyed the corpse to the Medical Officer should be taken and this fact may also be proved by affidavit under Section 296 of the Code of Criminal Procedure, 1973.