The auditor completed the audit of financial statements with an unquified opinion. The client company wanted to make a voluntary disclosure of some supplemental information to the financial statements in the 10-K, and the auditor agreed. However, the auditor found a highly material misstatement in the supplemental information. The client refused to correct the error.

Can the auditor still issue a report on the supplemental information? Explain. If yes, what should be the auditor's opinion on the supplemental information, and how should the auditor report it?