Property investors say a government proposal that could require all foreign property buyers to have an IRD number and New Zealand bank account will clarify whether foreign property investors are a significant problem.

The measure is part of the Taxation (Land Information and Offshore Persons Information) Bill announced by government ahead of the Budget, as a bid to put brakes on the Auckland housing market.

New Zealand Property Investors' Federation Executive Officer, Andrew King, hopes the data collected through the measure will put the ongoing speculation and debate to rest.

"A lot of this is speculation, we don't really know, so it will be good to have this clarified so that if there is a problem, then we can have definite data on it and laws can be made to address them."

King adds one year would be more appropriate as the two-year period will capture too many genuine investors.

"Traders and speculators want their money straight away, they generally buy and sell within a year and anything greater than a year means that it's harder for flexibility for rental property owners to actually do their investments."