TDs have strongly criticised fees of almost €300m which the Irish Bank Resolution Corporation (IBRC) has spent on winding up its operations.
Sinn Féin's Matt Carthy said that "exorbitant fees" paid by State agencies are a hangover of Celtic Tiger "madness".
These costs are "astronomical", he told the Oireachtas Public Accounts Committee.
Catherine Murphy, Social Democrat co-leader, said we need to know why the wind-down is taking so long.
The Department of Finance should be asked to appear before the committee, she added.
To the end of last year, the IBRC spent €294m on fees - with further fees of up to €33m anticipated before it is fully liquidated.
This would give a total of €327m spent on fees to finally shutter the IBRC.
The agency houses the former Anglo Irish and Irish Nationwide banks, which cost taxpayers €35bn when they collapsed in 2009.
John Hogan, Secretary General of Department of Finance, confirmed to the PAC that the conclusion of the wind-down has been pushed from the end of 2022 to the end of 2024.
Covid was cited as a factor, in part because it has delayed outstanding legal cases.
The intention is to "maximise the return for the state", Mr Hogan said in a letter.
Deputy Murphy warned that "the longer this goes on the more expensive it is going to be".
The update on the fees - which have been accrued to the end of last year - was included in correspondence to the PAC.
The committee will ask Mr Hogan to examine this expenditure, to ensure that it represents value for taxpayers.
The Comptroller and Auditor General said the fees do not go through accounts he audits, which is "standard enough".
Seamus McCarthy said he therefore "can't give any insurance in relation to the operation of controls."
Deputy Carthy said this "would reinforce my own view that we should ask the department [of Finance]" to ensure value for money is being secured.
Sinn Féin's Brian Stanley, who chairs the PAC, said "we will look for that".
The Comptroller also revealed that Tusla breached procurement rules on transactions worth over €6m last year.
Mr McCarthy told the committee that the agency made €6.3m of non-compliant procurement in 2020.
This was down from €7.1m in 2019, he noted.
He said that the issue has "been a constant since they were established", adding that Tusla relies "on the systems in HSE in some respects".
Transport Infrastructure Ireland - which spent €1.5bn last year - was also found to be non-compliant with procurement rules, Mr McCarthy said.
And a number of agencies were found to have failed to secure value for tax payers money, including the National Transport Authority, the National Oil Reserves Agency, and the Residential Tenancies Board.
