Production of additional evidence: permitted only by narrow exceptions and only with written reasons and response opportunity. Additional evidence on appeal is prohibited except where the adjudicating authority wrongly refused admissible evidence, the appellant was prevented by sufficient cause from producing evidence when called or relevant to a ground of appeal, or where the order was made without sufficient opportunity to adduce evidence. Admission under these exceptions requires written reasons, and the adjudicating authority or its authorised officer must be given a reasonable opportunity to examine, cross examine, or rebut the evidence. The Appellate Authority or Tribunal may also direct production of documents or witness examination to dispose of the appeal.