Attorney General Chris Finlayson says NZ First leader Winston Peters' bill for a register of foreign-owned land would breach the privacy of foreign land owners and "expose them to stigma and hostility" on social media.
Peters' member's bill would set up a public register which listed the names and nationalities of foreign property buyers, the amount and value of land involved, and the regions in which the land was situated.
In the Attorney General's vetting of the bill, Finlayson said the bill would breach the Bill of Rights Act because publicly naming foreign owners was a breach of privacy.
Finlayson said having information on foreign-owned New Zealand land was "an important and significant objective" but naming the owners was not required.
"The impact of the loss of privacy for foreign nationals ... goes beyond losing the ability to keep personal investment transactions from public view. Publication of their name in many cases will be enough to expose the means of contacting them through social media and expose them to stigma and hostility from persons who resent foreign ownership."
In response, Peters said Finlayson's conclusion it would breach the privacy of foreign buyers was "balderdash" and could only be reached by a "plutocratic officious nerd."
"Privacy is of course what money launderers and investors trying to evade their own country's jurisdiction love the most, and the Attorney-General seems to be right up their alley."
Publication of their name in many cases will be enough to expose the means of contacting them through social media and expose them to stigma and hostility from persons who resent foreign ownership.
The Attorney General's report does not mean the bill must be withdrawn - Bill of Rights Act vetting is a standard part of the process.
Peters has argued a register is needed for a more accurate measure of the amount of land owned by foreigners in New Zealand, currently estimated at 1-3 per cent.
Although the Overseas Investment Office records major or sensitive purchases, it is not a comprehensive list.
In his report, Finlayson said the register as proposed by Peters would not be comprehensive because it would not include land already in foreign hands or land owned by New Zealand citizens living overseas.
Nor did it provide for people to be removed from the register if they subsequently moved to New Zealand so were no longer 'foreign owners.'
His report said there were other ways to measure the extent of foreign-owned land, such as making the register anonymous or subject to the Privacy Act which would limit the breach of privacy.
Peters said the Attorney General's reasoning would also mean foreign visitors could not be charged for hospital bills or foreign students charged international student fees.
"The Attorney-General would be wise to stop forlornly posing as a modern Blackstone of the Antipodes and settle for plain common sense rulings," Mr Peters said.
Sir William Blackstone was an 18th Century British jurist and Tory politician renowned for his Commentaries on the Law of England.
Peters said there were similar registers of foreign ownership in countries such as Australia.
"Does it mean that all other countries that have restrictions on foreign ownership and the laws to identify them are somehow breaching basic human rights? Of course, not."
Labour has also called for a register of foreign ownership and wants to ban foreign buyers buying houses in New Zealand unless they are building a house themselves.