New rules around the export of swamp kauri won't work because they rely on the honesty of the companies selling them, Labour says.
The Government announced on Monday it was going to force exporters to meet tighter regulations, following an outcry in Northland.
Rough cuts from the massive, highly prized 50,000-year-old trees have been turning up for sale overseas despite export restrictions.
Existing rules say only stumps or finished products can be sent offshore.
Local iwi and environment groups claim rough cut planks and logs have been exported in contravention of those rules.
They also say logs have been superficially scratched and sent overseas described as Maori carvings to get them out under the finished product rule.
Labour MP Kelvin Davis, who represents the far north Te Tai Tokerau electorate, says the new measures rely on exporters telling the Ministry for Primary Industries how much kauri they've extracted.
"They won't make an iota of difference because they rely on honesty... and these contractors refuse to reveal how much of this ancient toanga they've dug up and shipped off overseas," he said.
"It's not clear what happens if they don't."
The Greens have welcomed the changes but still want an independent investigation into kauri extraction, which they say is destroying wetlands.
Primary Industries Minister Nathan Guy says the measures will be enacted quickly and his ministry will closely monitor them.
The changes include:
* Operators must notify all finished products for export approval and MPI will inspect the product
* Operators must notify the Northland council of all extraction activities, and this information will be shared with MPI
* MPI will visit all extraction sites as part of its milling approval process
* There will be additional MPI resources in Whangarei to increase inspections of sawmills and export consignments
* MPI will increase its oversight of swamp kauri export consignments and work with Customs to ensure any items not complying with the Forests Act will not be able to leave New Zealand
* There will be regular monitoring of international trade listings and action will be taken when advertisements are misleading, or where they indicate there could be non-compliance with the export controls.