The full name of the investigation was the Commission of Inquiry into Certain Matters relating to Taxation. The Commissioner was Sir Ronald Davison. The Commission concluded that there were no grounds supporting the allegations of fraud and corruption. The inquiry was characterized by extensive litigation, both during and afterwards and by an extremely high level of public interest. The Commission was established in September 1994 and reported nearly three years later in August 1997.
The Commission became popularly known as the Winebox Inquiry, as Winston Peters brought the documents at the centre of the allegations to Parliament in a winebox. The wine box contained numerous documents relating to a range of transactions entered into or contemplated by a number of parties.
In 1994 the Winebox Inquiry was formed. The terms of reference of the Commission of Inquiry required it to report upon whether the Inland Revenue Department and the Serious Fraud Office had acted in a lawful, proper and competent manner in dealing with the relevant transactions[which?], and to examine whether any changes to the criminal or tax laws should be made to protect New Zealand's income tax base from the effects of fraud, evasion and avoidance.
The genesis for the inquiry lay in repeated claims by Winston Peters of criminality associated with tax planning undertaken by some of New Zealand’s largest companies (some involving tax deals with the Cook Islands) as well as fraud and incompetence by both the Inland Revenue Department and the Serious Fraud Office. Public pressure eventually forced the government to set up the inquiry.
The Magnum Transaction
The transaction at the centre of the Winebox Inquiry was known as the “Magnum” transaction. In fact the documents in the winebox outlined more than 60 different transactions involving a range of parties.
In September 1986 a European Pacific Investments subsidiary based in New Zealand lent money to another subsidiary based in the Cook Islands. Withholding taxes on that loan were paid to the Cook Islands Tax Office of $2 million and a tax certificate for that sum was duly issued. European Pacific presented this certificate to the tax office in New Zealand, and as there was no further New Zealand tax to pay, paid a dividend to an investor, called Magnum, a brewery. In the Cook Islands, another member of the EPI group received a financial benefit from the Cook Islands government, and simultaneously forgave a loan to the government. The net effect: one EPI company received a benefit of $850,000 from the Cook Islands government, and yet another subsidiary received a New Zealand tax credit of $2 million.
Although the Commission concluded that there was no fraud or incompetence, controversy surrounded these rulings.
The Law Commission identifies  four court cases which arose during or immediately after the inquiry; this indicates the degree of litigation and controversy surrounding it. Other court cases also surfaced, for example against TVNZ, in relation to the inquiry's subject matter.
Subsequent appeals were made seeking to overturn the Commission’s findings. Most notable of these was a case for judicial review taken by Winston Peters against the Commissioner, which effectively upheld Davison’s findings. A subsequent ruling of the Court of Appeal  overturned this finding and referred the matter back to the High Court. The final ruling of the High Court  was that four of the findings of the commission which related to the Magnum transaction were struck out as a result of errors in law by the commission and associated criticisms of Winston Peters to the extent they related to those errors in law[clarification needed]. The Court stated:
- “Declarations (1) to (4) [striking out the findings relating to Magnum] are not, and are not intended to suggest, findings by this Court that there has been fraud or incompetence. The effect of the declarations is as if the words in the Winebox report to which they relate were crossed out, leaving the Winebox report incomplete in these respects. Declaration (5) [striking out the related criticism of Winston Peters] will ameliorate the criticisms made of the plaintiff which are related to those errors. The Winebox report remains otherwise unaffected.”
Unsurprisingly both sides to the debate claimed victory.
Changes to tax laws relating to the claiming of foreign tax credits were made. New rules relating to disclosure to the Inland Revenue Department and penalties for non-compliance were introduced.
New Zealand, Commission of Inquiry into Certain Matters Relating to Taxation, 1997
- The Role of Public Inquiries at page 53 Archived February 9, 2013, at the Wayback Machine.
- The Honourable Winston Raymond Peters v The Right Honourable Sir Ronald Keith Davison 1998 NZAR LEXIS 6;  NZAR 309 Archived March 3, 2016, at the Wayback Machine.
- Peters v Davison 1998 NZLR LEXIS 70;  2 NZLR 164 Archived January 10, 2013, at the Wayback Machine.
- Peters v Davison  3 NZLR 744 Archived February 12, 2012, at the Wayback Machine.
- Peters v Davison  3 NZLR 744 at paragraph 94 Archived February 12, 2012, at the Wayback Machine.
- Summary by Des Trigg[dead link]
- Molloy, Tony (21 July 2008). "Tony Molloy: 'Time and time again, courts labelled Winebox deal fraud'". The New Zealand Herald. Retrieved 3 December 2011.
- "Editorial: SFO could be soon restored". The New Zealand Herald. 14 July 2008. Retrieved 3 December 2011.