The police in New Caledonia are investigating a massive acid leak at the Vale Inco nickel plant that killed thousands of fish and other species.
Thousands of litres of sulphuric acid spilt into the North Bay River last Wednesday, but news of the leak took some time to become public.
Technicians have managed to neutralise the high acid levels, but environmental organisations say the damage has already been done.
Our correspondent, Claudine Wery, says the police are trying to find out what happened as there's uncertainty.
"There's an investigation by police. Vale said that the leak was about 1 to 5000 litres of acid. Little by little people have learned what happened at the unit. And in fact it could be 20 000 litres of acid."