A Corruption and Crime Commission report has exposed a deep mistrust of Police Commissioner Karl O'Callaghan by his department's executive director.
In a statement to the CCC, Greg Italiano claimed he never bothered to raise questions with Mr O'Callaghan about the use of his corporate credit card because he believed the Commissioner had lost his "ethical compass".
The opinion from the State's most senior civilian in the police force is contained in a CCC report which cleared Mr O'Callaghan of any misconduct.
According to the CCC report, Mr Italiano's claims were unsatisfactory and without substance.
In the fallout from the investigation, Mr Italiano has taken leave and it is unclear whether he will return to his job.
The comments about Mr O'Callaghan could explain why Premier Colin Barnett said he had "concerns" about the CCC report before making it public yesterday.
Mr Barnett told Parliament he still had confidence in Mr O'Callaghan and Cabinet would consider renewing his contract on Monday.
The CCC found Mr Italiano's claims were not supported by evidence.
"Ultimately, the commission concluded that the allegations made by Mr Italiano could not be substantiated," the CCC found.
"Mr Italiano did not ultimately identify any particular matter, transaction or series of transactions in support of his concerns."
In a written statement to the CCC in January, Mr Italiano said he stopped signing off on Mr O'Callaghan's credit card expenditure in 2010 because he felt uncomfortable about doing so.
"I no longer wished to be put in the position of having to approve his expenditure," Mr Italiano said.
"What bothered me was a pattern of behaviour in which I felt there were transactions that were questionable.
"I would describe this as a loss of an ethical compass in that decisions or behaviour could always be justified by an explanation regardless of how reasonable the average person might find that explanation.
"This is not just my view but the view, based on experience, of other senior and less senior officers in the WA Police executive."
Mr O'Callaghan described his executive director's views as "bizarre" and "unfathomable".
"As far as I'm concerned it is absolutely unfathomable - I have no idea," Mr O'Callaghan said.
"I have no issue whatsoever with people taking genuine concerns to the CCC but I do take issue if those concerns are raised without foundation or are ill-conceived and that's what we have in this case."
He described Mr Italiano's evidence as "a kick in the guts" and said there was no possibility of them working together again.
But a decision on Mr Italiano's future lies with Public Sector Commissioner Mal Wauchope, who also gave advice to the Premier about the credit card report.
Mr Barnett said recommendations by the CCC about "anomalous" use of police and public sector corporate credit cards would be acted on.
"There is no evidence or finding of deliberate or intentional breach of procedures, nor of reckless or intentional disregard for procedures and compliance requirements," Mr Barnett said.
Mr O'Callaghan, who was under investigation for 10 months over his credit card use and what he said publicly in relation to the 2011 Perth Hills fires, says he was hopeful of being reappointment before his contract expires on Wednesday.
"I have made no secret of the fact I have been disappointed with how long this process has taken, particularly due to the sensitivities surrounding the negotiation of my contract," Mr O'Callaghan said.
The CCC inquiry was launched after a legal and policy staffer inside Mr O'Callaghan's office complained to the watchdog.
Mr Italiano was then compelled by the CCC to give evidence about the allegations.