The operator of New Caledonia's Goro nickel plant, Vale-Inco, says last week's diesel spill at a power unit near its main site caused only minor pollution.
The territory's daily newspaper says an equipment malfunction saw 2,000 litres of fuel leak out but it was contained in a retention area apart from some 50 litres that flowed onto the ground.
The company says the incident, which has had no impact on the flora and fauna, was inmmediately reported to the authorities.
In April, there was a serious acid leak at the plant which caused concern over the enterprise's impact on the environment.
The Goro plant, which is to start nickel production next year, is next to a lagoon that has been declared a UNESCO World Heritage Site.