The head of the federal anti-corruption watchdog faces calls to step aside after he was found to have engaged in misconduct by not investigating six people associated with the illegal robodebt scheme.
The inspector of the National Anti-Corruption Commission reviewed its decision not to pursue six people mentioned in the robodebt royal commission report, finding commissioner Paul Brereton didn't recuse himself after a conflict of interest.
A review of the decision not to investigate the robodebt referral should be conducted by an appropriate person, the watchdog's inspector Gail Furness recommended.
Mr Brereton declared he had a close association with one of the people but failed to appoint a delegate and remove himself from the decision-making, the inspector said.
As part of the review, a retired judge opined the decision "was affected by apprehended bias".
It means a reasonable person may think the decision wasn't made in an impartial manner.
No suggestions of actual bias and no findings of intentional wrongdoing or other impropriety were made.
"In light of the conflict of interest, the NACC commissioner should have not only designated a delegate but removed himself from the related decision-making processes and limited his exposure to the relevant factual information," the inspector's report states.
"This was not done."
Fellow at the Centre for Public Integrity Will Partlett, who researches anti-corruption commissions, said the review's finding was significant.
"It was not unlawful, but it does raise questions about decision management at the top of the National Anti-Corruption Commission and raises questions about if the commissioner should resign," Associate Professor Partlett told AAP.
"He should resign because the commissioner should be above all forms of reproach and this finding means he is unable to be in that position."
Assoc Prof Partlett said commission's actions had created the perception the body had not acted in the public interest.
"In this regard, the NACC did not understand its role in playing as a guardian of broadly looking into breaches of public trust."
Leading campaigner against robodebt Asher Wolf said victims of the scheme needed justice.
"The administrative failures to ensure justice over robodebt is indicative of defects in Australia's mechanisms of democracy," she told AAP.
"We need stronger responses to human rights breaches. It's time Australia had a Human Rights Act to prevent future robodebt-type failures"
Between 2016 and 2019, the former coalition government's scheme recovered more than $750 million from almost 400,000 people.
Many welfare recipients were falsely accused of owing the government money and robodebt was linked to several suicides.
Opposition Leader Peter Dutton said Mr Brereton still had public trust.
"It's important to point out that he has statutory independence and decisions that he makes all of the commission makes should be respected," he said.
Independent MP Helen Haines, who was a key proponent of a federal anti-corruption body, welcomed the decision to reconsider the robodebt investigation.
"The investigation and findings by the Inspector mean accountability and scrutiny of decisions made by the commission can be provided without the political pressure or under direction from the government," she said.
Greens senator David Shoebridge joined calls for Mr Brereton to resign.
"Given these findings by the inspector it is hard to see how the NACC can survive and retain its credibility without immediate and unambiguous accountability," he said.
"This is not about just revisiting the robodebt decision, it is now about Commissioner Brereton's future."
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