Opposition Leader Mark McGowan has offered his support to the senior bureaucrat who has taken leave after accusing Police Commissioner Karl O'Callaghan of losing his "ethical compass".
WA Police executive director Greg Italiano was quoted in a Corruption and Crime Commission report which became public on Wednesday when Premier Colin Barnett tabled it in Parliament.
On the eve of the report's tabling, Mr Italiano went on leave and Mr O'Callaghan, who has been cleared of misconduct, has since described the pair's working relationship as "untenable".
But Mr McGowan is concerned that Mr Italiano is being unfairly targeted for doing what he is required to do under the CCC Act.
"I understand he wasn't the one who initiated the complaint (to the CCC)," Mr McGowan said. "He was called upon by the CCC to provide evidence. I don't think he needs to be treated badly. I think the Government needs to make sure people who come forward with evidence when called by organisations like the CCC are treated properly and don't lose their positions."
He said Mr Italiano should be treated with dignity and respect.
The career public servant's future rests with the public service commissioner Mal Wauchope, who will consider whether Mr Italiano can be transferred to another department or paid out.
Mr O'Callaghan is expected to be reappointed on Monday.
In January, Mr Italiano provided a written statement to the CCC which said Mr O'Callaghan and his office had lost its "ethical compass". He also said there was a "pattern of behaviour" in regard to credit card use by the Commissioner that concerned him and others in the police hierarchy.
But when Mr Italiano was called to a private hearing at the CCC, his position changed.
The CCC concluded that Mr Italiano did not identify any "substantive matter" to support his claims about Mr O'Callaghan's behaviour or conduct other than his reference to The Filth. Mr O'Callaghan plays in a band called The Filth.