Auditor General was a position within the Federation government responsible for looking over records and ensuring that Federation agencies, including Starfleet, were run efficiently. These audits were carried out by efficiency auditors.
In 2275, a team of auditors was dispatched to the USS Enterprise to ensure that Captain James Kirk was running his ship efficiently. The auditors found issues in Pavel Chekov's security department, but these complaints were later dropped. (TOS novel: Death Count)