If the auditor is unable to obtain sufficient appropriate audit evidence and:
(a) concludes that the possible effects on the financial statements of undetected misstatements, if any, could be material but not pervasive, the auditor shall qualify the opinion; or
(b) if the auditor concludes that the possible effects on the financial statements of undetected misstatements, if any, could be both material and pervasive so that a qualification of the opinion would be inadequate to communicate the gravity of the situation, the auditor shall:
(i) Withdraw from the audit, where practicable and possible under applicable law or regulation; or
(ii) If withdrawal from the audit before issuing the auditor’s report is not practicable or possible, disclaim an opinion on the financial statements (ISA 705, para. 13).