Answer: The internal auditor discovered it when performing a routine audit of expense reimbursements
Step-by-step explanation:
Marcus Lane, was a geologist who travelled all over North America and South America and this results in several expense reimbursements. Lane engaged in fraudulent activity by double booking his air travel.
He used cheaper ticket for the actual flight and more expensive ticket was returned for credit. But, he submitted the expensive ticket for reimbursement.
The fraud was discovered by the internal auditor while doing a routine audit of expense reimbursements. He was terminated and he agreed to pay the money back.