Additional evidence in appeal cannot be used to create a fresh defence against valuation evidence once proceedings have begun.

Additional evidence in appeal may be admitted only where admissible material was wrongly excluded, was not within the party's knowledge despite due diligence, or is necessary for proper adjudication or other substantial cause. The two proposed letters were not treated as mere clarification of existing records; they were aimed at challenging comparability of prices used for valuation and at weakening the Department's evidence. That was viewed as impermissible creation of evidence after proceedings had begun, so the request to admit them was refused.

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Issues: Whether the appellants were entitled to adduce additional evidence in the pending appeal.

Analysis: The governing principle for receiving additional evidence is that it may be admitted only where the lower authority wrongly refused admissible evidence, the evidence was not within the party's knowledge despite due diligence, or the appellate forum requires it to enable proper adjudication or for substantial cause. The proposed letters were examined and found to be no mere clarification of material already on record. Instead, they were directed at showing that the prices relied upon by the Department were not comparable and at undermining the evidence supporting the impugned valuation. Such material would amount to creating evidence after the commencement of proceedings, which is not permissible. The cited precedents were distinguished because, in those matters, the additional documents only amplified material already existing or related to correspondence that had begun before the adjudication proceedings.

Conclusion: The request to admit the two letters as additional evidence was not allowed.

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