Foreign Minister Penny Wong says a decision to appoint a public servant who oversaw robodebt to a plum $17,000 a week job was made before damning evidence emerged from the royal commission into the illegal scheme.
Kathryn Campbell was made an adviser on the AUKUS security partnership in June last year, after she left the top job at the foreign affairs department.
Ms Campbell was the secretary for the human services and social services departments which oversaw robodebt, and has been grilled at the royal commission over the scheme.
Senator Wong told a Senate estimates hearing the decision to appoint the public servant had been made before the inquiry began.
She said evidence that went "beyond what (she) would have anticipated" came out.
Greens senator Barbara Pocock questioned at Monday's hearing why the appointment was made, given the Albanese government already had the findings that the scheme was unlawful.
In response, Senator Wong said it wouldn't be "fair to say that there was an interrogation yet of how that illegality came about".
Senator Pocock asked why the government hadn't ended Ms Campbell's employment, describing her as the "captain of the ship" for the rollout of robodebt.
Senator Wong said referring to Ms Campbell that way "assumes the knowledge of what has subsequently occurred in the commission".
David Williamson, a Department of the Prime Minister and Cabinet's official, said Ms Campbell had "indicated an interest" in any roles in the federal public service relating to defence.
Ms Campbell told the royal commission she had made a "significant oversight" after submitting a potentially misleading document to a cabinet committee.
The Centrelink debt scheme ended in a $1.8 billion settlement after it was found to be unlawful.
