A report on the situation at Vale's nickel processing plant in New Caledonia is expected to be delivered to the government of the Southern Province today.
Operations have been suspended at its Goro plant for just over a week after 100,000 litres of effluent, containing some acid, ended up in a creek.
Local radio reports that members of the indigenous population are blocking the site's entrance.
It also reports that about 50 maintenance staff are on site, amid uncertainty for those not working during the suspension over whether they will be paid.
A spokesperson for Vale International says the plant's operations will resume shortly, but did not give a timeframe.
If the plant were to close, 14,000 jobs could be at stake.