More than half of the spending by former Waikato DHB boss Nigel Murray has been found to be unjustified.
A State Services Commission report released on Thursday found over $101,000 spent by Dr Murray was unauthorised, while more than $120,000 was unjustified.
Unjustified spending included personal expenditure, spending which was more "extravagant" than policy requirements, and spending with no evidence of a justified business purpose.
Commissioner Peter Hughes says Dr Murray's conduct fell short of what is expected in a public sector position.
The report found the chair of the board appears to have retrospectively authorised at least 20 of Dr Murray's travel applications.
At least a third of all Dr Murray's authorised travel applications had "no or inadequate evidence of business purpose".
The report also says the board failed to contact Dr Murray's previous employer when hiring him. Mr Hughes says had they done so, it "would have raised a red flag".
Dr Murray would not be interview by the inquiry.
The commissioner has referred his report to the Serious Fraud Office.
Nigel Murray's spending
Dr Murray spent $218,166 on expenses in three years at the Waikato DHB.
He was paid a $560,000 salary, and the DHB paid $106,000 to a recruitment agency to hire him.
He resigned the role in October last year after an internal investigation, saying he'd repay some of the overspending. That investigation reportedly cost $150,000.
The State Services Commission began its own investigation in November.
DHB chairman Bob Simcock initially defended Dr Murray's spending, saying in February last year the CEO was just doing his job.
Dr Simcock resigned after the extent of Dr Murray's overspending was exposed.
"I regret that we employed Nigel Murray four years ago," he told the Waikato Times in November.
"If I knew what I know now, we would not have employed Nigel Murray. Had he not done what he did, then I would be getting on with the business that we were trying to achieve."