Production of additional evidence on appeal is limited to narrow exceptions with written reasons and opportunity to rebut. An appellant is precluded from producing additional oral or documentary evidence before the appellate authority or Appellate Tribunal except where the earlier authority wrongly excluded admissible evidence, the appellant was prevented by sufficient cause from producing it, the evidence is newly relevant to a ground of appeal but previously unproduceable for sufficient cause, or the order was made without affording opportunity to adduce relevant evidence. Admission requires the appellate authority or Tribunal to record written reasons, and the adjudicating authority or an authorised officer must be given reasonable opportunity to examine or cross examine witnesses or to produce rebuttal evidence; the appellate body may also direct document production or witness examination.