But the real killer blow was delivered this morning when Finance Secretary Jenny Wilkinson went before Senate estimates and delivered a series of bombshells indicating just how high a price PwC is likely pay with Treasury and Finance departments, which are clearly furious with the firm.

Last week, even before Treasury referred the matter for criminal investigation, the Finance Department directed PwC to stand down anyone working on Commonwealth contracts who was directly involved in, or who had knowledge of, the scandal.

Any partners involved in exploiting the leak who have since moved to other big four consulting groups are now in the spotlight.

This directive appears to go beyond the 50 or so staff and partners who were named in the emails released early this month detailing how PwC partners exploited the information for commercial gain.

Wilkinson says that if this breach had occurred under the Management Advisory Services Panel – the all powerful panel that governs Commonwealth contracts for the private sector – it would have given Finance grounds to tear up all PwC’s current contracts.

Senate estimates was then told that Commonwealth business with PwC for the financial year to date – up to May 16 – totalled $255 million. PwC is estimated to generate annual revenue of about $3 billion.

More interesting are the fresh directives that go to the heart of whether PwC is effectively shut out of all government business for the foreseeable future.

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On the day the directive went out to PwC to stand down staff, the Finance Department published a procurement policy note on its website reminding Commonwealth officials that when considering external contractors they must “consider previous behaviour, including ethical conduct”.

These government procurement officers, controlling billions in contracts each year, will not have a hard time working out what Wilkinson thinks of PwC’s ethical conduct.

Not after she detailed just how the release of the 144 pages of emails in May, detailing how PwC’s attempts to exploit the confidential information, starkly contrasted with its initial response that the matter was limited to Collins.

“This additional information raised serious concerns about the broader culture within PwC and undermined our confidence in their earlier engagements around this matter,” she said.

Whatever happens from here, PwC Australia has lost its biggest customer for the forseeable future. And its corporate business might just follow.

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