The Inland Revenue Department will get an extra $132 million in this week's Budget to chase those who don't pay their fair share of tax.
Prime Minister John Key said a small number of New Zealanders did not meet their tax obligations, and the extra money would help the department crack down on them over the next five years.
"Property speculators and those that haven't paid their fair share of tax, and just generally people who have set up tax evasion schemes, or tax avoidance schemes that aren't lawful," Mr Key said.
"So it's really looking more in the high net worth end and also the corporate end."
The move was expected to increase the Crown's gross revenue by nearly $300 million during the next five years, he said.