Australia’s biggest superannuation funds have either frozen, or are reviewing, future work contracts with PricewaterhouseCoopers Australia, as the fallout from the tax leaks scandal proves costly for the embattled firm.

Four of the country’s biggest funds, AustralianSuper, Australian Retirement Trust, Hesta and Aware Super, say they will not enter into new contracts with PwC, after the professional services firm used confidential information obtained through its work for the government for commercial gain.

Another significant fund, Rest, is reviewing its arrangements with PwC, while Cbus and Hostplus both said they were monitoring the issue.

The funds are among the largest financial managers in Australia, by size and member numbers, collectively overseeing well over $1tn of retirement savings.

A spokesperson for Aware Super said while its past dealings with PwC had been exemplary, it had frozen any new contracts with the firm.

“Like many others we’re deeply disappointed by the reported failures of governance, accountability and culture at PwC,” the spokesperson said.

“We look forward to the full extent of this issue being promptly investigated and addressed.”

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A spokesperson for AustralianSuper said PwC mainly did audit work for the fund and that the current contract would be reviewed later this year.

“AustralianSuper is concerned with the ongoing revelations around PwC and as a result has frozen any new contracts with PwC,” the spokesperson said.

PwC Australia is subject to multiple investigations, including a criminal probe, after its now former international tax chief Peter Collins fed intelligence on government plans to toughen multinational tax laws to colleagues to win overseas business and potentially rob Australia of tax revenue.

Several PwC partners have left the firm, including Collins, while others are on leave pending the outcome of an investigation. PwC Australia chief executive Tom Seymour resigned last month.

PwC declined to comment on Friday. The firm has previously published an open apology and acknowledged that the actions were “completely unacceptable”.

Analysis of superannuation fund documents shows that the industry largely uses major accounting firms, including PwC, Deloitte, KPMG and Ernst & Young, for audit and tax services.

The need for both internal and external audits means the work must be shared among multiple firms.

The boycott by several super funds comes on top of PwC being largely shut out of future federal government contracts as well as being scrutinised by state governments, which includes an inquiry in New South Wales into the use of consultants.

The tax leaks scandal has triggered a broader debate over conflicts of interest in professional services firms. Regulators around the world, in particular in the UK, have raised concerns over the ability of firms to properly audit accounts, while also offering lucrative consulting contracts to those same clients.

Ian Ramsay, who formerly headed a federal government inquiry into auditor independence, said the issues in PwC’s tax practise at the heart of the scandal were pressuring other parts of the business.

“PwC operates at so many levels, in terms of the diverse, complex services they operate, the vast majority of which as of right now are not under question for their conduct, but they are feeling threatened.

“We just don’t know to what degree those significant cultural failings extend.”