A chief audit executive assigned an internal auditor to perform an assurance engagement.

If an auditor concluded a major audit finding based on hearsay evidence, it indicates a lack of demonstration of due professional care. Due professional care requires that conclusions be based on evidence that is sufficient, reliable, relevant, and useful to support audit findings and recommendations. Relying on hearsay does not meet these criteria and undermines the audit's reliability and credibility.

IIA standards related to due professional care, which dictate that internal auditors must gather adequate factual evidence to support their findings and conclusions.