The English 'variable standard' of unreasonableness, which heightens scrutiny according to the degree of interference with human rights, is not part of Australian administrative law and cannot be superimposed on the Wednesbury standard. Fresh evidence cannot be admitted on certiorari merely to demonstrate that the decision-maker made an error of fact. The duty to inquire exception remains narrow: it arises only where it is obvious that material is readily available which is centrally relevant to the decision.
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