Presumption of document authenticity: prosecution-tendered documents presumed true unless rebutted, and admissible despite being unstamped. When a document produced, seized, or received from abroad is tendered by the prosecution against an accused, the court shall, unless the accused proves otherwise, presume the truth of its contents and that signatures or handwriting and any execution or attestation are genuine; such documents must be admitted in evidence even if not duly stamped, provided they are otherwise admissible.