[36-A. Presumption as to documents in certain cases. Where any document is produced by any person or has been seized from the custody or control of any person, in either case, under this Act or under any other law and such document is tendered by the prosecution in evidence against him or against him and any other person who is tried jointly with him, the Court shall,
(a) unless the contrary is proved by such person, presume
(b) admit the document in evidence, notwithstanding that it is not duly stamped, if such document is otherwise admissible in evidence.]