The Auditor General's reports are certainly one of the main sources of questioning at estimates hearings. If the Auditor General has found difficulties with a particular program, waste or inefficiency, certainly senators will focus on those programs and have detailed questions about them.
The committees are also able to ask the Auditor General for further details and specific reports on specific subjects.
The Senate itself has passed resolutions asking for detailed audit reports on particular programs and parts of departments.
The audit process and the auditor's reports are certainly a very major source, and these audit reports are performance reports. They're not just checking the figures; they're looking at the performance of departments and agencies and their efficiency.