“Where we find any evidence of wrongdoing, those involved will be held accountable and action will be taken,” Elliott said. “The board will also lead a process to ensure consequences will be applied to senior executives, both past and present, including myself, where appropriate”, largely in reference to remuneration and bonuses.

It was a huge blow to a bank whose shares have lagged its rivals by between 8 and 18 per cent this year, as interest-rate expectations and the New Zealand economic outlook weighed heavily on its share value.

Investors are now assessing the financial implications of the probes.

If ASIC gathers enough evidence and successfully litigates in court, which could be years away – if it ever gets there – ANZ faces a maximum penalty of $780 million, a modest sum relative to the $7.4 billion profit it posted last year.

The real hit to ANZ will come from the potential revenue it will be forced to forego from governments reluctant to deal with the bank while an investigation is conducted. ANZ has reportedly already missed out on three potential government contracts over the scandal.

“Certainly, the government is going to think twice about using ANZ,” said Mark Humphery-Jenner, a finance academic from the University of New South Wales.

“If the allegations are proven, this would have cost the taxpayer money because the taxpayer is going to be paying a higher interest on debt. And if proven, there’s an element of dishonesty … by making themselves look more experienced than they actually were.”

Brian Johnson, a long-serving banking analyst at MST Financial, has likened the hot water ANZ finds itself in to the scandal that engulfed PwC after revelations the consulting giant misused confidential government information to help corporate clients avoid paying tax.

Since that erupted about 18 months ago, PwC has slashed hundreds of jobs, sold off its lucrative government consulting practice to private equity firm Allegro Funds for $1, and been investigated by federal police and politicians.

“Either [the ANZ markets unit] was very, very fortunate on the day the bond was priced, or the fact it happened is telling you they didn’t have the processes in place,” Johnson said.

“The problem is that when you’ve got people incentivised to generate a profit, perhaps it becomes acceptable to step outside of the normal rules, and that’s what ASIC’s investigating.”

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Elliott last month played down ASIC’s investigation, describing it as a routine “please explain” notice from the corporate regulator. Days later, ASIC chairman Joe Longo shot down that suggestion, noting an investigation “by definition [means] we suspect a contravention of the law”.

The corporate regulator has assigned some of its most senior investigators to uncover what happened at ANZ, indicating how serious it is viewing the allegations. But it’s too early to tell what this means for the bank, or even the future of Elliott, who was widely expected to resign later this year after an eight-year tenure as chief executive.

“Shayne Elliott has been in the role for quite some time, and he was close to moving on anyway, so sometimes things like this bring that forward,” said Omkar Joshi, founder and chief investment officer of Opal Capital Management.

“If it escalates from here, you can make the case you want someone from the outside, a clean slate to look to fix things, but you have a look at the history at Westpac … and Commbank … they had internal candidates [after their chief executives resigned].”

Analysts and investors are keenly watching, especially as the New Zealand regulator, Financial Markets Authority, investigates its own allegations of market manipulation over a $NZ2.5 billion inflation-linked government bond issued two years ago.

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