Two former public servants referred to the anti-corruption watchdog by the royal commission into robodebt have been found to have engaged in serious corrupt conduct while former prime minister, Scott Morrison, has been cleared.

The long-awaited report into potential corruption related to the unlawful income averaging scheme, released on Wednesday, covered the six referrals made by royal commissioner Catherine Holmes in 2023, which were restricted from the public view in a sealed chapter.

The National Anti-Corruption Commission’s investigation, which began in February 2025 after an independent reviewer said it should occur, examined the actions of the five former public servants and former prime minister relating to the development, approval and implementation of the robodebt scheme in 2015, 2017 and 2018.

The attorney-general, Michelle Rowland, thanked the Nacc and said the federal government would move to table the previously sealed chapter.

The commission’s findings named former human services department official Mark Withnell as having intentionally misled Department of Social Services officers during the preparation of a cabinet submission in 2015.

The former social services deputy secretary Serena Wilson was also found to have engaged in serious corrupt conduct by intentionally misleading the Commonwealth Ombudsman during an investigation in 2017.

The Nacc’s deputy commissioner Kylie Kilgour, said publishing the report “provides transparency as to how those conclusions were reached”.

The other four names referred to the Nacc but not found to have engaged in any corrupt conduct included Morrison, Kathryn Campbell, Annette Musolino and Catherine Halbert.

The report found Morrison’s failure to detect misleading advice from the department was caused by social services and human services departments both failing to advise him and other ministers that new laws were required.

Guardian Australia has contacted Morrison for a response.

Campbell was one of two named by the Australia Public Service Commission in 2024 after it found twelve public servants, including Campbell and former department head Renée Leon, breached the code of conduct 97 times during their involvement in the robodebt program.

More details to follow