The Serious Fraud Office (SFO) has ended its probe into the former chief executive of the Waikato District Health Board.
A State Services Commission (SSC) investigation last year found more than half of the $218,000 spent by Nigel Murray on travel and accommodation over three years was unjustified.
Serious Fraud Office director Julie Read said the investigation has been closed because committing the resources required to prove criminal charges beyond reasonable doubt was not in the public interest.
She said there would need to be extensive investigations in Canada - where Mr Murray worked previously.
The SSC investigation found Dr Murray's conduct did not meet the minimum standards expected of him as a chief executive in the state sector.
The SFO said it agreed with those conclusions.
Dr Murray resigned in late 2017.
The DHB was without a permanent chief executive after Dr Murray stepped down until last month when Kevin Snee resigned from running the Hawke's Bay DHB to take up the position.
Health Minister David Clark replaced the DHB board with a commissioner in May.
The chairman of the DHB, Bob Simcock, stepped down after a report came out from the Auditor-General on Dr Murray's spending.