Two former government ministers will be grilled over their knowledge of the unlawful robodebt scheme when a royal commission into the program resumes.
Former human services minister Alan Tudge and former social services minister Christian Porter will be among the key witnesses during hearings this week at the robodebt royal commission.
The Centrelink debt recovery scheme used annual tax office data to calculate fortnightly earnings and automatically issue welfare debt notices.
The program recovered more than $750 million from more than 380,000 people and led to several people taking their own lives while being pursued for false debts.
The controversial scheme was set up in 2015 and was allowed to continue until 2019, despite significant criticism of how the scheme operated.
Mr Tudge was in the portfolio of human services between 2016 and 2017 while Mr Porter was in his role as social services minister between 2015 and 2017.
The latest block of hearings will examine what department officials knew about the potential illegality of the scheme, and how officials communicated information with the government and other staff.
Other witnesses that will be questioned during this week's group of hearings include Rachelle Miller, who was Mr Tudge's former media adviser, along with Service Australia's former chief operating officer Annette Musolino, who will testify on Monday.
Senior officials from the department will also take to the stand including the Department of Human Services' former general council Maris Stipnieks and the Deprtment of Social Services former deputy secretary Nathan Williamson.
The commission heard on Friday that officials ignored external legal advice that the robodebt sheme was illegal.
Department officials said they had concern the government would face substantial legal risk over the scheme.
Former Social Services principal legal officer Anna Fredericks told the commission independent legal advice would have caused "reputational damage" to the government and the departments administering the program.
She said if the independent advice was acted on, the robodebt scheme would have been changed or stopped altogether.
