The president of New Caledonia's Southern Province Cynthia Ligeard has ordered immediate suspension of operations at the Vale nickel processing plant at Goro after an estimated 100,000 litres of effluent ended up in a creek.
The spill contained some acid but it is not immediately clear how strong the concentration was.
The provincial government has sent a joint mission with the environmental authority to the six-billion US dollar plant for an evaluation of the spill.
It's the fifth such spill in five years at the Goro plant.
Vale has confirmed that there's been an incident but has given no details yet.
The French High Commissioner, the President of the territorial government of New Caledonia, as well as the mayors of the municipalities of Mont-Dore and Yate have been advised of the spill.
The Southern Province president has activated a crisis unit to evaluate the impact of this industrial accident and to put in place urgent measures to limit its effect.
In February, five New Caledonian environmental groups won nearly half a million US dollars in compensation from the Vale nickel company over a major acid spill at its plant five years ago.