Tiwai Point aluminium smelter. Photo: RNZ / Nate McKinnon The government made a multimillion-dollar offer to the multinational last December to advance the clean-up, but in March pulled the plug on negotiations. "In relation to the proposed Crown payment, Rio Tinto indicated that the ... payment was too low in quantum," a Treasury email in January this year says. At the same time, it said the company had rejected a request to provide a financial guarantee over the clean-up. Earlier, last October, Treasury told Robertson Rio Tinto appeared to be seeking multiple meetings with him and others to "circumvent" the Treasury-led negotiating team and strategy.