Some two tons of fuel oil leaked into the sea from a ship near the Italian southern port city of Taranto on Thursday, local media reported.
A pool of some tens of meters has appeared on the sea because of the fuel oil spill from a ship flying the Turkish flag, which was moored at the cargo port of Taranto for loading of waste material.
Local coast guard has circumscribed the contaminated area with floating barriers and stared the operation of cleaning up fuel oil spillage.
The waste materials were reportedly sourced from ILVA, Italy's biggest steel company. It has been in newspaper headlines in the past weeks for a major legal dispute over whether its biggest European plant in Taranto has to halt production due to an ongoing clampdown on pollution.
Prosecutors have ordered the company to partially stop production and make upgrades to clean up its pollution blamed for high local cancer rates.
The case has sparked a national debate over whether the site, located in an impoverished region of recession-hit Italy, should be shut down threatening the jobs of some 12,000 workers.
According to local media, Economic Development Minister Corrado Passera, Justice Minister Paola Severino and Environment Minister Corrado Clini will travel to Taranto on Friday to conduct an inspection.
Earlier this week, Clini warned that uncertainty about the future of ILVA is putting "Italy's entire industrial system at risk." The World Health Organization will help monitor pollution levels as the plant, he said.
Italy's government, which was ready to appeal to the constitutional court against the ruling to halt production, has recently allocated 336 million euros (415 million U.S. dollars) for environmental mediation and recovery at the site.
On Thursday, labor unions in Taranto held a two-hour strike and protest march that blocked major roads around the plant.
ILVA was founded in 1905, nationalized in 1933 and then bought in 1995 by the privately-held group Riva. Last year, it produced 8.5 million tons of steel, almost a third of the Italian total steel production.