Four current or former public servants have breached the Australian Public Service code of conduct in relation to the Robodebt scheme, according to the preliminary findings of an independent investigation.
Last year, the Australian Public Service Commission (APSC) launched an investigation into 16 public servants who were identified by the royal commission into the unlawful debt recovery program as being involved in it.
The royal commission said the scheme was an extraordinary saga of "incompetence and cowardice" that was "neither fair, nor legal".
It recommended a number of people be referred for civil and criminal prosecution.
The findings form part of the ongoing APSC investigation into whether the public servants in question breached their responsibilities as described in the Code of Conduct.
The Code of Conduct, which is enshrined in the Public Service Act, requires public servants to act "honestly and with integrity".
It requires they maintain confidentiality and use their power and inside information appropriately.
It also forbids them from providing "false and misleading information" in the course of their work.
The APSC has not disclosed which elements of the code the four individuals are accused of breaching.
Breaching the code is not an offence, but can carry sanctions or lead to dismissal.
Another 11 individuals remain under investigation. One individual has been cleared of breaching the code.
Former Home Affairs secretary Mike Pezzullo was last year dismissed from his role after an independent investigation found he had breached the Code of Conduct on 14 occasions.
Those breaches included using his position to gain personal advantage, being "disrespectful" of ministers and failing to disclose a conflict of interest.