While conducting an engagement in the procurement department, the internal auditor noticed that the department...

Given the unusual observation in the travel expenses reports, the most appropriate next step for the internal auditor is to investigate whether there are any special arrangements regarding senior management travel. This investigation could reveal explanations for the absence of typical travel-related expenses, such as pre-paid packages, special corporate arrangements, or even potentially unreported expenses, which could be critical for compliance and ethical standards.

Internal Auditing Standards on performing audit work and investigating anomalies.