Final answer:
The internal auditor's responsibility is to report the matter to the audit committee and request funding for outside service providers to help investigate the possible fraud.
Step-by-step explanation:
The internal auditor's responsibility, after noting red flags that suggest fraud may be present, is to report the matter to the audit committee and request funding for outside service providers to help investigate the possible fraud. This action is necessary because internal auditors do not have the authority to carry out investigations on their own. By reporting to the audit committee, they can ensure that the matter is escalated to the appropriate level and sufficient resources are allocated for the investigation.