The Government offered to pay millions of dollars to Rio Tinto, just months after it promised no direct subsidies would be paid to the owner of the Tiwai Point aluminum smelter.
The deal, which was never taken up, is revealed for the first time in letters released under the OIA.
Finance Minister Grant Robertson is not calling it a subsidy, saying in return for the money the multinational was expected to retain jobs, clean up the site and help the Southland economy transition to other industries.
Phil Pennington spoke to Susie Ferguson.