More than half the vessels inspected by the Navy in its latest fishery patrol were found to be breaking the law.
The HMNZS Otago has just returned from a two-month patrol of fisheries in the Pacific, where they uncovered commercial fishing operators without fishing licences and catching sharks without declaring it.
In a joint operation with the Minister for Primary Industries the Navy boarded 71 vessels and discovered 40 vessels had made 48 breaches of domestic and international laws.
Greenpeace investigator Tim McKinnel says the number of breaches by long line fishers is worrying, but not surprising.
"It's a massive problem, not just environmentally but in terms of human rights as well."
Six breaches were found on 19 vessels last year but the Minister for Primary Industries Nathan Guy insists the problem's not getting worse.
"I don’t think there’s a trend that it's increasing,” he says.
"What it means is we know where these vessels are."
The captain of the HMNZS Otago says the operation was helped by the diversity of his crew.
"We actually have people who spoke Mandarin, Spanish, Japanese and Russian so we really covered all bases."
A source has told Newshub the vessels breaching the law were mostly Chinese and Taiwanese, but the Government won't confirm that, saying it'll compromise any defendant's right to a fair trial in their home countries.
But Labour's fisheries spokesman Rino Tirikatene wants diplomacy put aside to protect our backyard.
"Our Government needs to intervene and we need to apply pressure along with our international partners to the Chinese Government and also blacklist these vessels,” Mr Tirikatene says.
Mr McKinnell says there is no doubt the Pacific needs to be better patrolled.
"The small island states are particularly vulnerable, it's a vast area, it's really difficult to patrol.”
He says nobody wants to talk about the human rights abuses and illegal fishing activity.
"We've got these industrial corporations emptying the oceans and these types of breaches are a regular feature."
The first phase of the patrol took place in the south-west Pacific in the waters of Fiji, Tuvalu, Niue and Tokelau where 34 vessels were checked.
The second phase was in international waters to the north of the New Zealand Exclusive Economic Zone and 37 vessels were checked.
Ministry for Primary Industries CEO Andrew Coleman says they boarded and inspected tuna long-liners flagged to a number of different countries which were fishing for mainly albacore, yellowfin and bigeye tuna.
The 48 breaches of domestic and international laws included having unmarked fishing gear, lack of fishing licences, non-use of bird scaring devices and non-declaration of shark catch.
It's now up to the relevant countries to investigate breaches uncovered by the two-month patrol and Nathan Guy says his officials will be making sure that happens.