Ms Mason said disclosure documents made it clear there had been "backroom deals" and the wreck removal agreement was "a sham" and the Crown "knew it too".
Representatives from Motiti Island's Ngai te Hapu, the trust and the local Maori Council called on the tribunal to force the Government to enforce a 2011 Maritime New Zealand statutory notice which says the wreck must be removed.
Ngai te Hapu spokesperson Buddy Mikaere told the tribunal that the "bottom line" for him and the other Motiti Island hapu was for the complete removal of the wreck and all the debris.
"This is a sad day ... It almost makes me weep that under the Treaty of Waitangi and its principles the Government has acted less than honourably, putting a foreign company and its interests ahead of tangata whenua and our interests.
"The Crown says signing its secret deal was not a breach of the Treaty nor was the $10.4 million an incentive payment, we believe that is nonsense," he said.
"We say, we the owners, should have a say in all of this and we'd been denied that."
Mr Mikaere said the Crown deed agreement failed to recognise Astrolabe Reef as a taonga and as "customary owners" of the reef, the Government should have consulted Ngai te Hapu as required under the Treaty of Waitangi principles.
"But it's not just a Maori issue, it's a whole community issue because everybody has various reasons why they want this environmental disaster fixed," he said.
Ngai te Hapu's lawyer Tom Bennion described the $10.4 million as a "success fee" and an incentive for the Government to facilitate the shipping company's end goal of leaving the wreck on the reef. It would save the Rena's owner and insurers a substantial amount of money to do so, he said.
Mr Mikaere said he had been told the cost to remove the rest of the wreck and the debris would be between $500 million to $1 billion.
The inquiry continues today, with the Crown responding.
