Presumption as to documents creates rebuttable presumption of contents and handwriting and allows admissibility despite insufficient stamping. When a document produced, seized, or received from outside India and tendered by the prosecution against the person from whose custody it came or a jointly tried person, the court shall, unless the contrary is proved, presume the truth of the contents and the genuineness of any signature or handwriting, and in the case of executed or attested documents that they were executed or attested by the persons who purportedly did so; such documents are admissible even if not duly stamped, if otherwise admissible.