A complicated oil salvage from a war-time wreck off the coast of Whangārei is under consideration.
The Niagara went down in June 1940, after hitting a mine laid by a Nazi Navy vessel in the Hauraki shipping route during World War II.
Previous salvage missions focused on retrieving the ship's secret cargo of gold bars. However, it's the black gold still on board that is causing concern today.
Underwater explorer and author of Deep Water Gold: The story of RMS Niagara, Keith Gordon, estimates there may be more than a thousand tonnes of oil remaining in the ship's intact tanks.
"It could be a ticking time bomb out there, an ecological time bomb, that in time is going to create a lot of problems," he told Newshub Nation.
The possibility of an oil spill three times larger than the Rena, which ran aground off Tauranga in 2011, has Whangārei residents and iwi concerned.
"We saw first hand with the Rena, it would have a massive impact. We just don't seem well-enough equipped here in Aotearoa to deal with it," says Juliane Chetham of Patuharakeke.
"The alternative is unthinkable, they really need to look at extracting the oil and preventing a major catastrophe."
Julie Anne Genter is the minister responsible for the wreck, and admits previous governments did little to address the situation.
"The last thing we want to see is a catastrophic oil spill in this area," she says.
"Best case scenario the oil is already gone, or it's so completely degraded that it wouldn't pose a risk, but we need to find out."
On Ms Genter's instruction, Maritime NZ is following the UK's wreck management programme. It is currently at the first step, doing a detailed desktop analysis, and will report back its findings in August.
If there is sufficient risk, the second step will be to do an on-site survey using cameras and sonar. If that survey finds a spill is likely, the third step will be to extract the oil.
"Normally the owner of the wreck would fund this type of recovery, but it's been such a long time there's really no way to recover the costs from the original owners," says Ms Genter.
Clive Sharp has recovered oil from wrecks before, he says the technology to assess and remove the fuel has improved considerably.
"The initial survey would be around $2 million, and to actually carry on afterwards and do the extraction would be a total of around $10 million, give or take 10 percent," he says.
That's a fraction of what it would cost to clean up a major spill - the Rena cost taxpayers $47 million to clean up more than 350 tonnes of oil.
However, time may be running out for the Niagara. The wreck is corroding away and there are fears it may collapse in the next decade.
"It's too early for me to commit to a particular timeframe other than we've asked the officials to go away and do work on the risk assessment as soon as possible," says Ms Genter.
"That should give us a better idea both of what our options are, what the costs may be and what the timeframes are."
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