Western Australia's former Liberal National government under Colin Barnett has been criticised in an inquiry as poor economic managers "beyond belief" who squandered the mining boom and caused the state's current record debt and deficit.
The WA government's revenue more than doubled to $28 billion mostly due to iron ore prices during the decade of the mining boom to 2013.
But instead of building strong budget surpluses, spending under the Barnett government soared, causing the current record deficit of about $3 billion and debt due to peak at $40 billion-plus in the next few years, the report found.
Respected former WA Treasury boss John Langoulant released the $1.1 million near 1000-page report on Tuesday, which was ordered by Labor Premier Mark McGowan shortly after he won last year's election.
It has been dismissed as a political witch-hunt by the WA Liberals and Nationals.
"Sure we spent too much, what we didn't pay enough regard to were the risks that sit within our finances which are considerable," Mr Langoulant said of the Barnett government.
"The problem was the government spent too much and took its eye off its risk management responsibilities ... our royalties were what needed to be managed.
"They (current Labor government) have got a set of finances which are beyond belief."
The biggest culprit for waste was the multi-billion dollar Royalties for Regions program, which was forced on the Liberals by the Nationals as a condition of forming government in 2008.
At one stage it was costing more than $1 billion a year in mining royalties to be spent on unknown projects in the bush not subject to "reasonable standards" of scrutiny, the report found.
"We identified the Royalties for Regions program as probably the main factor that caused difficulties for the government, it destabilised financial management, the system clogged up the cabinet process," Mr Langoulant said.
WA Nationals leader Mia Davies said she was proud of the program's legacy.
One of the most damning criticisms was the awarding of a $4.3 billion contract to global company Serco to run the new Fiona Stanley Hospital in Perth without a business case.
Also cited was soaring spending, especially public sector salaries and in health which had become by far the nation's highest per capita, while management of projects, contracts, governance and transparency were deficient, the report found.
A key recommendation was that governments heed the advice of the public service, with former premier Mr Barnett accused of snubbing Treasury and Auditor General warnings on high spending and that high iron ore prices would not last forever.
Mr Barnett refused to be interviewed for the inquiry but responded in writing.
Liberal leader and former Treasurer Mike Nahan was interviewed.
He rejected Mr McGowan's call during question time in parliament to apologise for financial mismanagement, saying no one, including Treasury, Labor or Mr Langoulant had predicted the iron ore price collapse.
