“Regardless of who they put in charge,it’s still paid for and run by PwC. Promising to release a summary of the findings is not the same thing as making the findings available to the public,” she said.

“We can’t have any confidence in it. This is a matter for the National Anti-Corruption Commission where it will be properly investigated.”

PwC also announced that Tony O’Malley,head of its global legal business solutions team,had been appointed as chief risk and ethics leader of its Australian business with immediate effect.

The stakes are high.The Australian Financial Review reported that three of the largest global corporations – Apple,Google and Microsoft – are among those targeted with confidential information about the government’s plans to focus on tax avoidance.

PwC declined to comment about the trio.

Senator Deborah O’Neill – who chairs the Corporations and Financial Services Committee that released a damning 148-page document this month revealing the scale of the firm’s profiteering fromleaking confidential government tax plans to potential clients – said the cultural problems the scandal highlighted raised questions about the firm’s business.

“You cannot provide a level of assurance as required by our financial markets,let alone by the government,if you are operating out of a model that is so clearly devoid of an ethical backbone,” O’Neill said.

Following recent resignations from other leadership roles,Stubbins has appointed Rob Silverwood as head of its Financial Advisory business.

Nicole Salimbeni will lead a response plan for establishing appropriate governance and structures.

On Monday,PwC announced that Seymour would “retire from the partnership on 30 September,2023,to enable an orderly transition”.

Seymour has also stood down from the board of a well-connected military contractor that is chaired by former defence minister Christopher Pyne.

Seymour had his profile removed as a director of Australian Missile Corporation last week.

The privately owned company was set up as a potential strategic partner of the Defence Department in establishing an Australian-based Guided Weapons and Explosive Ordnance Enterprise. It is fully owned by defence contractor Nioa,which is owned by its chief executive,Robert Nioa.

On Monday,Nioa said Seymour resigned last month after a board restructure.

“Mr Seymour was appointed to the advisory board of the Australian Missile Corporation – a Nioa Group company in June 2022 – before the AMC board and Nioa board became one under a company restructure earlier this year,” Nioa said.

The AMC website shows that no other board members have resigned,including former Australian soldier and Victoria Cross recipient Mark Donaldson.

Seymour led PwC’s tax operation when confidential information was widely shared within the firm and marketed to multinational clients.

He confirmed he had received the emails but denied he was aware the information was from a breach of confidentiality agreement by PwC partner Peter Collins.

Collins received a two-year professional ban from the Tax Practitioners Board earlier this year in response to his breach of the confidentiality agreement.

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