The appellant shall not be allowed to produce before the Appellate Authority or the Appellate Tribunal any evidence, whether oral or documentary, other than the evidence produced by him during the course of the proceedings before the adjudicating authority or, as the case may be, the Appellate Authority except in the following circumstances, namely:-

(a) where the adjudicating authority or, as the case may be, the Appellate Authority has refused to admit evidence which ought to have been admitted; or

(b) where the appellant was prevented by sufficient cause from producing the evidence which he was called upon to produce by the adjudicating authority or, as the case may be, the Appellate Authority; or

(c) where the appellant was prevented by sufficient cause from producing before the adjudicating authority or, as the case may be, the Appellate Authority any evidence which is relevant to any ground of appeal; or

(d) where the adjudicating authority or, as the case may be, the Appellate Authority has made the order appealed against without giving sufficient opportunity to the appellant to adduce evidence relevant to any ground of appeal.

No evidence shall be admitted under sub-rule (1) unless the Appellate Authority or the Appellate Tribunal records in writing the reasons for its admission.

The Appellate Authority or the Appellate Tribunal shall not take any evidence produced under sub-rule (1) unless the adjudicating authority or an officer authorised in this behalf by the said authority has been allowed a reasonable opportunity -

(a) to examine the evidence or document or to cross-examine any witness produced by the appellant; or

(b) to produce any evidence or any witness in rebuttal of the evidence produced by the appellant under sub-rule (1).

Nothing contained in this rule shall affect the power of the Appellate Authority or the Appellate Tribunal to direct the production of any document, or the examination of any witness, to enable it to dispose of the appeal.