A "please explain" has been issued to the national anti-corruption commission over its decision to not chase six public officials caught up in an illegal debt recovery program.
The commission announced it would not launch a corruption investigation into the public officials connected to the robodebt scheme that siphoned more than $750 million from vulnerable Australians and was linked to several suicides.
It found their conduct had been fully explored through a royal commission into the welfare debt collection scheme and multiple investigations into the same matter wasn't necessary.
Almost 900 individual complaints were made to the Inspector of the National Anti-Corruption Commission about the decision.
Many alleged corrupt conduct or maladministration by the commission, Gail Furness said.
"I also note that there has also been much public commentary," the inspector said in a statement on Thursday announcing her inquiry.
"I anticipate that I will make my findings public in due course."
Five of the six officials have already been referred to the Australian Public Service Commission.
The robodebt scheme used annual tax office data to calculate average earnings and automatically issued debt notices to welfare recipients between 2015 and 2019.
The royal commission recommended people be referred for criminal prosecution.
