Indiana’s State Budget Committee has chosen Deloitte to find out how the state managed to mishandle over $500 million in tax revenue.

Last December, state officials learned to their dismay that $320 in corporate tax revenue somehow had not been deposited in Indiana’s general fund for a number of years. Then in April, they discovered that another $206 million in local income tax funds had not been distributed to Indiana’s counties in the past 14 months.

After conducting an initial review, the state decided that it lacked the necessary audit capabilities to identify the source of the problem and it began looking for an external auditor. After 10 firms bid on the job, Deloitte won on Monday, according to the Associated Press.

Now the firm will need to scope out the audit and will probably end up conducting the audit as well. State officials want the auditors to examine both the state’s overall tax collection system and the technology behind it. That should be a sizeable enough job for the Big Four firm to handle.