The prime minister's description of the independent body that investigates corruption in NSW as a "kangaroo court" has been called "deeply offensive".
NSW Independent Commission Against Corruption Commissioner Stephen Rushton has defended the agency, saying references to the ICAC as a "kangaroo court" weren't just misleading but were also untrue.
People who made those comments were "buffoons", he told a parliamentary review on Monday.
Last month Prime Minister Scott Morrison criticised the ICAC while under pressure to commit to a federal anti-corruption body.
"I'm very critical of some of the ICACs, particularly in NSW," Mr Morrison said.
He compared the ICAC's model of holding public hearings to a "kangaroo court" and chided its investigation into former premier Gladys Berejiklian.
That inquiry into disgraced former NSW MP Daryl Maguire revealed Ms Berejiklian had previously been in a personal relationship with him.
"To those buffoons who have repeatedly described this commission as a kangaroo court, I would say three things," Mr Rushton said on Monday.
"First, it is deeply offensive to the hard-working staff of the commission. It undermines the institution.
"Second, there are vast differences between the functions of the commission and a court.
"To describe us as a kangaroo court is not just misleading, but untrue."
"To make an uninformed comment that this commission is a kangaroo court has a real capacity to undermine the commission's work, and just as importantly, public confidence in public administration," he said.
The head of the anti-corruption watchdog Peter Hall also took a thinly veiled swipe at Mr Morrison, saying his comments were "misguided and unfounded".
"Corruption involves acts performed under conditions of great secrecy, often concealed and there is seldom an eyewitness witness to it," Mr Hall said.
"Occasionally, there is misguided and unfounded criticism of one or more in our community, of the commission's powers and its work.
"Whatever the motive or the purpose behind such criticism may be, a proper understanding of the legal conditions, processes of the oversight safeguards, will reveal to the misguided critic that he or she is simply wrong."
He acknowledged ICAC's wide-ranging powers but said all public inquiries underwent considerations to protect against reputational damage.
Asked about ICAC's timeline for producing reports, Senior Counsel assisting ICAC Inspector Bruce McClintock accepted it was an issue.
Parliamentary Review Committee member Ron Hoenig said individuals not found corrupt under Operation Aero had struggled to find employment, had banks threaten to close their accounts, and were featured in nightly news reports.
"There have been situations where I have intervened where I thought it was getting problematic," Mr McClintock said.
He added ICAC's ability to rule a person corrupt meant the commission had to be absolutely meticulous.
"It will be monstrously unjust if it was done in a sloppy way."
He repeated his colleague's refrain that the ICAC also did not function like a court with witnesses, a judge and barristers.
He said ICAC decisions by their nature took time.
"It's been a persistent regret of mine that I've never been able to get across ... to members of the public that ICAC is not a court," Mr McClintock said.
"It's a specialist, investigative agency of the state of New South Wales."
Opposition Leader Chris Minns said he had not seen the comments from the Chief Commissioner, but NSW Labor supported the ICAC, and if elected would work to establish independent funding for the agency.
"(The ICAC has) been the subject of criticisms, and that's what happens in a free society," Mr Minns said.
"I'd say to those critics, imagine what the state would be without the Independent Commission Against Corruption.
"It's my belief that a tonne of corruption doesn't take place before it even begins, simply because the institution is in place."
