The international accounting giant PricewaterhouseCoopers had won its most illustrious mandate to date, the first external audit of the finances of the Vatican. That was until nearly four months ago, when its work was suddenly put on ice.

The suspension of its contract was a “blow for financial transparency” wrote the Catholic news weekly The Tablet.

“The work of PwC would have been the first of its kind and was going to provide a complete picture of Holy See finances, including a valuation of assets,” the paper wrote. “But in April the firm’s work was unilaterally suspended exposing a power struggle between Australian Cardinal George Pell – who the Pope appointed to reform Vatican finances – and senior members of the Roman Curia.”

The irony in this, however, is that the Holy See is already far more transparent than its prospective auditor, PwC. Indeed, it is far more transparent than all four global audit firms put together.

“The Big Four have strayed from their role of verifying financial accounts for all stakeholders, to be ‘accountants of fortune’.”

At the stroke of a keyboard anybody can pull up the 2015 financial statements of the Vatican Bank and there find a full set of accounts, replete with detail about “related party transactions”. There is also an independent auditor’s report by PwC’s peer, Deloitte.

This is the Vatican Bank, mind you, not the church and the city-state, which are yet to face external audit. Yet it is no mean irony that this institution, long scrutinised for corruption and secrecy, displays greater openness than those who preach daily to governments about laws and policies – the Big Four accounting firms, PwC, KPMG, Deloitte and Ernst & Young.

As Deloitte notes in the 2015 accounts: “The financial statements present fairly, in all material aspects, the financial position of Istituto per le Opere di Religione [Vatican Bank] and its financial performance and its cash flows for the year then ended in accordance with International Financial Reporting Standards.”

As part of a series of stories at michaelwest.com.au about the immense power and opacity of the global accounting firms, further questions were posed last week.

Contacting communications people at each firm, this question was casually put: “By the way, who audits your firm?” There were four responses:

“I don’t know.”

“Umm … ah … I should know this off the top of my head but I don’t.”

“I’d have to check that out for you.”

“I don’t know that.”

This was unsurprising. The sacred role of the “communications” operative, particularly with respect to the inscrutable Big Four, is not to know, then to courteously deny requests to speak with somebody who might know, then to ask for questions to be emailed.

In this case, however, they appeared genuinely not to know. What a stonking paradox it is that the world’s most powerful institutions – yes, more powerful than the Vatican – can’t and won’t reveal who audits them. All four firms later failed to respond to emailed questions.

Bear in mind that they themselves audit 98 per cent of the world’s largest multinational companies, rack up combined revenues of $170 billion, and are the principal architects of tax avoidance schemes that cost governments and taxpayers an estimated $1.3 trillion a year.

To borrow from the Satires of the Roman poet Juvenal, Quis custodiet ipsos custodes? Who will guard the guards?

The short answer is nobody. The guards are guarding themselves. And not only are they guarding themselves but they are writing the laws of nations.

Martin Lock, formerly the head of withholding tax for the Australian Tax Office, describes the sheer pervasiveness of the four firms, particularly in the area of formulating laws:

“These same stalwart firms are ensconced on the Board of Taxation, its working groups, CPA Australia, the Institute of Chartered Accountants and the ATO’s very own National Tax Liaison Group, which the ATO describes as ‘one of the ATO’s eight stewardship committees which addresses strategic issues to benefit Australia’s taxation and superannuation system’ and which ‘drives improvements ... to ... tax law interpretation, administration, design and policy (including technical issues); confidence in and compliance with the tax system; and ATO service delivery.’ ”

Then there are the millions of dollars lavished yearly by governments on the Big Four for consulting reports and advice, and staff “secondments” between the mega-firms and bureaucracies such as the tax office and the corporate regulator.

Is there any audit, any transparency or independent scrutiny of this vital public information? There is supposed to be. The big firms have a statutory obligation under the Corporations Act to produce a “transparency report” once a year, where they are required to disclose financial information “including revenues”. Amid pages of what can fairly be labelled “marketing fluff”, they take the narrowest possible definition of “financial information” and merely disclose revenue.

The approach is no better in Britain and other countries. As the University of New South Wales academic Jeff Knapp puts it: “The transparency reports are more of an exercise in public relations. The firms should be forced to be more transparent than they are.”

A simple word count tells the story, says Knapp. In Deloitte’s “Transparency Report 2015”, the words “audit quality” appear 31 times, “value” or “valuable” appear 22 times, “innovation” or “innovative” appear 20 times, “culture” appears 13 times and “excellence” 12 times. But the word “profit” does not appear once. There are no details of the $1 billion in non-audit services to non-audit clients and, in the list of audit clients, the names of their largest fee-paying customers, aggressive tax-minimising foreign multinationals, do not appear.

The Ernst & Young report is typical of the others. In the section on document-retention policy, the thing missing is the most relevant: the detail of the duration that documents are retained. Nothing on political donations, nothing on profits or partner charge-out rates, no proper breakdown of government revenue. KPMG’s report, for what it is worth, is slightly more useful than the rest.

George Rozvany, a former Big Four insider and head of tax for Allianz Australia, says the transparency reports were “touchy feely... more appropriate for a weekend magazine than the required financial disclosures of a major organisation”.

“It must be remembered that the Big Four win huge contracts from various levels of Australian government but fail to disclose government donations in their transparency reports, or for that matter entertainment expenses and identities of government officials entertained, and related party transactions with offshore tax shelters – all relevant considerations in appropriate transparency.”

In August 2015, Australia was one of 32 nations signing the Addis Tax Initiative to assist developing nations in improving the fairness, transparency, efficiency and effectiveness of their tax systems. So why let transparency go in Australia, Rozvany asks.

“The government announced in the budget that it would introduce whistleblower protection for individuals disclosing tax evasion in the private sector. This may work for those disclosing internally, but appears entirely inconsistent from a policy viewpoint for those attempting to examine such matters externally.”

Rozvany has called for the Big Four to be broken up due to their high market dominance and political and commercial influence.

“The Big Four have, under a Rasputin-like cloak of illusion, strayed from their original and critical role of verifying the accuracy of financial accounts for all stakeholders, to be ‘accountants of fortune’ merely representing the accounting position for multinationals and developing aggressive international tax-avoidance practices,” he told me last month.

In questions sent last week, again as part of the michaelwest.com.au reporting, each firm was asked about their disclosure failures; who insured them; whether they insured themselves, or even each other; and who audited them. They were also asked, again, to comment on the conflict of interest in advising multinational clients on tax while advising governments on tax reform.

No responses were forthcoming.

The corporate structure of each is made up of local partnerships – because partnerships don’t have to publicly report financial statements – which together operate under a global banner. Somebody, however, must audit their accounts in each jurisdiction and it can only be concluded that each firm audits their own.

If this is the case, it is the height of hypocrisy, as their business model, indeed the entire global system of commerce and corporate governance, is based on the foundations of external, independent audits. Yet here we have the world’s most powerful organisations completely unaccountable, even put to shame on corporate governance and transparency by the Vatican.

As an interesting aside, the hardliners of the Roman Curia argue there should be no external audit of the Vatican as it is a sovereign nation and sovereign nations audit themselves, as the Vatican does. If it is eventually audited by PwC or others, it would present a challenge. How, for instance, would the “property, plant and equipment” be valued? Would the Sistine Chapel and Michelangelo’s The Last Judgement be valued on replacement cost?

If external audit is foisted upon them, the hardliners may well quote the Gospel of Matthew in respect of PwC’s transparency and independence: You hypocrites! First remove the log from your own eye, and then you can see clearly to remove the speck from your brother’s.