A bungled expenses system for federal politicians spending taxpayer cash will suspend public reporting of those costs until mid-next year and be referred to the auditor-general after blowing out.
Assistant Trade Minister Tim Ayres told a Senate estimates committee hearing on Tuesday the troubled Parliamentary Expenses Management System was being hit with "severe delays" which would "need significant time and additional work" to rectify.
Senator Ayres said a decision to suspend the parliamentarian quarterly reports until the second half of 2023 was "not taken lightly".
"The requirement for public reporting is a key pillar of faith in our parliamentary system," he told the hearing.
"Maintaining transparency and integrity must be the highest priority."
Senator Ayres said the Special Minister of State Don Farrell will write to the Australian National Audit Office to suggest an audit or review of the system, which to date has cost $66 million.
Initially costed at $38.1m, the project is expected to cost up to $69 million by the time it's completed.
John Sheridan, from the finance department, said the problem with the reporting aspect of the system was that the function had not yet been built.
"It's not that it's failed," he said.
Public reporting would be delayed to prevent inaccurate expenditure reports being published and politicians having incorrect expenses attributed to them, the hearing was told.
The system was introduced in 2018 and was an initiative of the Turnbull government in the wake of the "Choppergate" scandal involving former speaker Bronwyn Bishop.
It is being operated by the Department of Finance and collects data on office and travel expenses, including printing, phone and internet bills.
But the system has been riddled with problems, including cases of overpayments and underpayments, and has been the subject of hundreds of complaints.
Since July, more than 80,000 claims made by parliamentarians had been paid.