The Rena wreck is a ‘cancerous tumour' and only full removal will restore the life-force, or mauri, of the Astrolabe Reef and Bay of Plenty people, a Waitangi Tribunal has heard.

Speaking during the urgent tribunal hearings in Tauranga this week, Mataatua District Maori Council chairman Maanu Paul compared the wreck of the ship that grounded on October 5, 2011 to cancer that needs to be completely removed.

Containers fall from the Rena ship back in 2011.

"It's like this. Last year, my mauri was bang-on, then I got diagnosed with pancreatic cancer. My mauri went down, the surgeon removed it, my mauri came up again. That's exactly how we want it to happen on the reef,” says Maanu.

Maanu is part of three iwi groups claiming leaving the wreck on the reef is a breach of the Treaty of Waitangi.

The Rena owners Daina Shipping and insurers The Swedish Club have applied for resource consent to the leave the remains of ship on the reef, about 25km off the coast of Tauranga.

Hapu are also calling on the Government to enforce a Maritime New Zealand statutory notice, which says the wreck must be removed.

Maanu says this is a new low in Treaty of Waitangi relationships claiming the Crown has obstructed and deliberately misinformed Maori throughout the process. Read more about those claims here.

He told the tribunal it must make the recommendation that the Government oppose the resource consent application. The government is yet to take a stance on the wreck's removal.

Waikato University's Professor of international law Alexander Gillespie told the hearing that full wreck removal falls under international best practice through the Nairobi International Convention on the Removal of Wrecks, 2007, but is not a legal requirement in New Zealand.

Adopted by an international conference in 2007, the convention provides the legal basis for states to remove, or have removed, shipwrecks that may have the potential to affect adversely the safety of lives, goods and property at sea, as well as the marine environment.

The convention provides the first set of uniform international rules aimed at ensuring the prompt and effective removal of wrecks located beyond the territorial sea.

Alexander believes this convention will become statutory for NZ in 2015.

'The way that the convention looks at wrecks as if they are hazards, not just in terms of navigation but social and environmental hazards,” says Alexander.

New Zealand is instead a signatory to the Convention on Biological Diversity which states governments must "support local populations to develop and implement remedial action in degraded areas where biological diversity has been reduced,” says Alexander.

About 100 people, many from Motiti island, were present for the hearing before a panel consisting of Judge Sarah Reeves, Sir Douglas Kidd, Sir Tamati Reedy and Ronald Crosby.

The hearing continues today with cross-examinations and Crown evidence.