law: Code of Criminal Procedure Act, 1973
  293.Reports of certain Government scientific
  
  experts.-
  (1) Any document purporting to be a report
  
  under the hand of a Government scientific expert to whom this section applies,
  
  upon any matter or thing duly submitted to him for examination or analysis and
  
  report in the course of any proceeding under this Code, may be used as evidence
  
  in any inquiry, trial or other proceeding under this Code.
  (2) The Court may, if it thinks fit, summon and examine any such expert as to
  
  the subject-matter of his report.
  (3) Where any such expert is summoned by a Court and he is unable to attend
  
  personally, he may, unless the Court has expressly directed him to appear
  
  personally, depute any responsible officer working with him to attend the
  
  Court, if such officer is conversant with the facts of the case and can
  
  satisfactorily depose in Court on his behalf.
  (4) This section applies to the following Government scientific experts,
  
  namely:-
  (a) any Chemical Examiner or Assistant Chemical Examiner to Government;
  (b) the Chief
  
  Inspector of Explosives;
  (c) the Director of the Finger Print Bureau;
  (d) the Director, Haffkeine Institute, 
  
   Bombay ;
  (e) the Director of a Central Forensic Science Laboratory or a State Forensic
  
  Science Laboratory;
  (f) the Serologist to the Government