Tax investigators are door-knocking speculators - including those seeking to avoid the brightline law - as they work to reclaim $80 million in unpaid property taxes.

New Inland Revenue (IRD) data shows as many as one in four transactions where the brightline rule applies could be non-compliant, including an increased number of deliberate dodges.

Last year alone, unpaid tax from speculators or "traders", including the brightline, was $23 million. Another $57 million went unpaid in property-related GST, rental income and taxes due from builders and developers.

IRD said some of those traders were actively trying to hide their property transactions


When do you have to pay tax on property profit?