The former head of the independent watchdog which investigated the agencies responsible for the robodebt program will be questioned by the royal commission. 

Michael Manthorpe served as Commonwealth Ombudsman between 2017 and 2021 and will front the commission on Wednesday. 

The commission is seeking to understand the role of the Ombudsman, whose initial report identified a number of flaws in the scheme but stopped short of declaring its “income averaging” debt calculation process unlawful.

This report, conducted before Mr Manthorpe took on the role, was used by the former coalition government to defend the scheme continuing. 

The robodebt scheme ran from 2015 to 2019 and used income averaging of tax office data to calculate and raise debts.

The commission is examining how the scheme was allowed to continue, given significant concerns about its legality raised by early 2017.

The commission previously heard senior human services officers “effectively co-wrote” the Ombudsman report into their own department’s dodgy scheme.

Senior public servant Jason McNamara readily admitted he was trying to influence the Ombudsman when they wrote to the department seeking feedback for the report about their shift to an automated debt recovery system.

More than $750 million from 380,000 people was unlawfully recovered through the program and the automated debt notices have been blamed for contributing to multiple suicides.

Former assistant ombudsman Louise Macleod and Deloitte partner Dr Elea Wurth will also be questioned. 

By Maeve Bannister in Canberra