A farming company part-owned by a Cabinet minister was able to give him a briefing about how the Government could protect its lucrative trade with Muslim countries by banning Jewish slaughtering.
Agriculture Minister David Carter supported the recommended law change but had to back down days before he was to be taken to court to justify it.
It is the second time this year Crown lawyers have had to leap to the defence of one of Parliament's wealthiest MPs - and this time in a case in which he was forced to admit getting basic facts wrong.
Carter was being sued by the Auckland Hebrew Congregation for changing the law in May to make traditional Jewish slaughter of animals illegal. The case was set to begin in the High Court at Wellington tomorrow - until an embarrassing backdown by Carter who on Friday overturned the ban he asked Cabinet to support.
The practice of shechita on poultry was declared no longer illegal while the Government also agreed to negotiate the ban on sheep.
New Zealand Jews will still have to import beef from Australia, where shechita is allowed.
Documents obtained by the Herald on Sunday appear to show Carter broke the rules governing his portfolio by considering trade implications when making the original decision.
An allegation of conflict of interest has been made because of that - he holds shares in a company which exports meat and met with senior managers who wanted a ban on shechita to protect their interests.
Carter was pulled back into line after lawyers told him he was allowed to consider only animal welfare issues. He had been advised trade with Muslim countries might suffer if it emerged kosher meat was allowed to be produced here while restrictions were placed on halal slaughter.
New Zealand requires halal meat be stunned before slaughter while kosher meat - which is killed only for a small domestic market - does not have the same restriction.
After getting the advice, Carter's office seems to have broken the rules again by giving opinions on trade to Prime Minister John Key in January and Trade Minister Tim Groser in February.
Emails obtained by the Herald on Sunday show Carter met in March with Silver Fern Farms Ltd chairman Eoin Garden and chief executive Keith Cooper, who said meat exports would suffer if shechita wasn't banned.
The MPs Register of Pecuniary Interests shows Carter owns shares in Silver Fern Farms Ltd and another major meat exporter to Muslim countries, Alliance Group Ltd.
Ministerial private secretary Natalie Nesbitt emailed senior Ministry of Agriculture and Fisheries officials: "Silverfern (sic) Farms CEO and chairman raised their opposition to an exemption being provided for shechita (kosher) slaughter ... with the minister this afternoon, among other matters."
She said concerns from Garden and Cooper included "trade risks (particularly to halal markets)" if a Jewish religious form of slaughter was allowed to continue in New Zealand.
Garden refused to detail the discussion when approached on Friday: "I don't think it is appropriate to comment on what was discussed at that meeting. I'll get legal direction on this."
Cooper initially said the concerns were in relation only to animal welfare, then later said "it was a long time ago" and he "doesn't recall any more detail".
Silver Fern Farms Ltd processes about 30 per cent of New Zealand's cattle market. With other stock, it exports more than $200 million of meat to the Middle East.
Carter owns three farms - a 1200ha cattle breeding property in Teddington, a fattening unit at Southbridge and shares in a property in Waiau.
Crown Law Office spokeswoman Jan Fulstow was unable to provide details of the cost of defending Carter over the shechita ban before press time.
It emerged in April that taxpayers paid $115,000 towards Carter's legal bills after a defamation scrap with former NZ First leader Winston Peters.
Fulstow contacted the Herald on Sunday on Friday to warn against printing material relating to the court case.
Fulstow said she was calling to warn about a confidentiality order at the urging of Carter's lawyer.
The call came within minutes of questions from the Herald on Sunday to Carter's ministerial office over Jewish community claims of a conflict of interest.
But much of the information used by the Herald on Sunday came through the Official Information Act, sought by Auckland's Jonathan Shenken, who became concerned his religious right to kosher meat would be threatened.
Shenken began and continued a decade-long research initiative which turned up concerns by MAF over the possible trade impacts of shechita - and eventually Carter's meeting with Silver Fern Farms Ltd. Other information included a High Court judgment released on Friday.
In the judgment, from Justice Alan Mackenzie, it was revealed that Carter had banned shechita slaughter of poultry, sheep and cows with the belief all could be imported from Australia.
But Carter's lack of knowledge was exposed in the judgment.
Judge Mackenzie reported that Carter had no idea it was not possible to import kosher chicken meat and that "his understanding was wrong".
His evidence also revealed he had no idea how much it could cost to import kosher meat - in the case of lamb, more than $120 a kilogram.
It was the judgment that also revealed Carter's office had repeatedly referred to shechita and trade after he had been told by lawyers he was not to do so.
According to the judgment, Carter's evidence said he did not know what was in the briefing papers sent from his office to Groser or Key that mentioned possible trade impacts from allowing shechita.
Carter did not respond to requests for an interview.
In a statement he said: "Claims that business interests determined my decision on the Commercial Slaughter Code of Welfare are totally baseless. Animal welfare was the primary consideration in making this decision and I have said many times that animal welfare is a priority of mine."
Prime Minister John Key - who has Jewish roots - said he had "no concerns" with the way Carter made his decision.
Leaders fear Jewish community would 'wither' because of shechita ban
Jonathan Shenken became concerned a decade ago that his religious practice was under threat.
There were changes planned to the Animal Welfare Code that posed a danger to domestic kosher meat, and while those at the syngogue made noises about legal action, he went his own way.
"I'm not a committee person. I decided to start doing some digging myself."
He peppered the Ministry of Agriculture and Forestry with Official Information Act (OIA) requests.
Learning to use the OIA was difficult and not made easier by officials who did not seem inclined to help, he said.
What emerged from all the paperwork he gained access to, he believed, was officials who were being urged by meat exporters to ban shechita, a form of animal slaughter that sees the intended meal prayed for before a ritualistic cutting of the throat.
It is a religious practice akin to that of the Muslim one of halal.
In NZ, animals are required to be stunned before being slaughtered, but the Jewish exemption to the stunning of kosher meat made it difficult for meat exporters, who feared Muslim countries would take umbrage over perceived preferential treatment of Jews. Muslims also oppose the stunning of animals.
Papers show that officials repeatedly spelled out to successive agriculture ministers how small the domestic kosher market was - about 2000 chickens a year and no more than 300 sheep - and that banning it could breach the Bill of Rights.
That advice continued right up to the current minister David Carter - who banned it anyway.
"My view is that Carter has only considered trade," said Shenken. "And when I found out the Minister had a pecuniary interest in exporting halal meat, it just blew my mind. There's a complete conflict on interest."
Shenken said the decision to ban shechita meat meant kosher meat would become inaccessable and signal the end of a 170-year Jewish community in New Zealand.
"The Jewish community worldwide knows of this. We can't attract teachers, rabbis, youth leaders. The community will wither."
NZ Jewish Council president Stephen Goodman said Carter's decision was met with "shock, dismay and disgust".
He said the community was currently seeking a rabbi for Auckland and potential applicants had raised the ban as a reason for not coming here.