धारा 131

When the maker or drawer of any bill of exchange, hundi or cheque has placed thereon any signature in token of his having accepted or drawn the same, or when any such bill of exchange, hundi or cheque has been altered by erasure, obliteration or otherwise, without the assent of all parties, it shall be presumed, unless the contrary is shown, that the signature is that of the person by whom it purports to have been made and that the bill of exchange, hundi or cheque has not been altered within the knowledge of all parties thereto.