Section 23. Evidence of documents

23. Evidence of documents.— (1) Every return furnished to the[1] [Authority] which has been certified by the[1] [Authority] to be a return so furnished, shall be deemed to be a return so furnished. (2) Every document, purporting to be certified by the[1] [Authority] to be a copy of a return so furnished, shall be deemed to be a copy of that return and shall be received in evidence as if it were the original return, unless some variation between it and the original return is proved.