Housing Minister Nick Smith has revealed that Government held data on the proportion of New Zealand homes owned by offshore buyers, which he says is very low compared to other countries.
A lack of data has been one of the main reasons that the National-led Government has given for rejecting calls from the Opposition to create a register for foreign purchases.
Data compiled by the IRD and released by the minister's office this afternoon showed that 11 per cent of landlords for New Zealand rental properties were offshore, though this figure included New Zealand expats.
The data was prepared for Finance Minister Bill English last June.
Smith said he could not recall seeing it last year but read it in March or April.
He said: "[The information] shows that the ... levels of overseas ownership of homes in New Zealand is small, that it's having no substantial impact on the market, and that making changes in that area are not going to have a material difference."
A Treasury analysis of the data said that it had its limitations, but showed that "the level of foreign ownership of New Zealand housing remains relatively low".
The IRD held data on the number of non-resident individuals reporting rental incomes or losses on New Zealand property.
It showed that out of 199,000 taxpayers who reported rental tax returns, 11 per cent were non-residents and 1 per cent were of unknown residency.
The briefing said it was important to note that the "non-resident" category included New Zealand citizens who lived overseas.
The data did not distinguish between expat New Zealanders and foreign buyers.
The non-resident category was rising more quickly than the resident category since 1997.
However, this could be a result of increased identification of previously unknown residents.
Smith: "This is a blind alley that we could beat our chest and have our officials do a whole lot of work [but] it's not an area that will make housing more affordable for Kiwis."
Treasury also cited data collected by BNZ and the Real Estate Institute of New Zealand, which estimated 8 per cent of residential sales were going to offshore buyers.
The BNZ-Reinz survey said that one of the main reasons that offshore people were buying New Zealand property was because they intended to live here.
Once these people were taken into account, the proportion of buyers who were not planning to live in New Zealand was 3.6 per cent.
Around 4.5 per cent of New Zealand property sales went to offshore vendors.
Smith said these figures were far lower than Australia, where as much as 22 per cent of sales were by offshore vendors.
He said he could not recall whether he requested the data.
"I get continuous briefings from my ministries all the time, I am up to my eyeballs in housing affordability, and this is just one piece of information..."