A PwC audit of robodebt that cost nearly $1 million did not raise concerns about the scheme’s illegality, a Senate estimates committee has heard.

The consultancy firm’s contracts with various government departments are in the spotlight after the discovery of a potential breach of treasury confidentiality by former partner Peter Collins.

During the royal commission into robodebt, it was revealed a 2017 audit of the illegal Centrelink program conducted by PwC was never finalised, despite being conducted as part of a contract worth almost $1 million.

Deputy chief executive Chris Birrer, representing the department’s royal commission response team, said PwC’s audit did not identify the illegality of the robodebt scheme.

“The [audit’s] focus really was on the operational delivery of the scheme,” Mr Birrer said.

“Some of their work did inform adjustments that were made to those online schemes to try to make it easier for people to engage with the scheme, but not the underlying legality.”

The robodebt scheme, which ran from 2015 to 2019, used annual tax office data to calculate average fortnightly earnings and automatically issue debt notices.

Hundreds of thousands of Australians were caught up in the debacle, which illegally recovered more than $750 million and was linked to several suicides.

In 2020, the then Coalition government agreed to pay more than $1.2 billion to settle a class action brought by welfare recipients who wrongly received massive debts under the unlawful scheme.

The scheme has since been the subject of a royal commission, launched under the Albanese government. Its final report is due on July 7.

On Wednesday, Greens senator Janet Rice pointed out the distress the scheme caused people who were pursued for debts they did not owe.

“It took some brave Centrelink staff to blow the whistle, but PwC were paid $1 million and didn’t raise any concerns about that?” she asked.

Mr Birrer said PwC delivered a PowerPoint presentation for then government services minister Alan Tudge.

“The issue that arose during the evidence that was heard at the royal commission was that a report wasn’t provided, and PwC did provide a draft report to the commission,” he said.

“We haven’t been able to find evidence that anyone in the department was provided a copy of the draft [report].”

Services Australia chief executive Rebecca Skinner said in light of the PwC scandal and robodebt royal commission, the department would make appropriate considerations in relation to consultancy work.

“Over the last three years. Services Australia has reduced the use of consultancies for work that we think public servants are quite capable of doing,” she said.

Asked if the department would seek a refund from PwC for the audit, Ms Skinner said she had not yet considered that action but would provide a response to senators.

-with  AAP