Vale has partially halted work at its Goro nickel operation in New Caledonia after an acid spill.
The company has begun investigations into the 690m³ spill of acid-containing solution, according to Reuters.
It has been contained and there have been no injuries or damage to the external environment, Vale said.
The $4.3bn project, expected to produce 60,000t of nickel a year, has been repeatedly delayed over the past 18 months.