"This oil slick definitely poses a threat to biodiversity," said Ezio Amato, one of the two UNEP consultants.
Earlier Tuesday in Rome, an Italian environmental agency which monitors the Mediterranean said the spill posed a heightened risk of cancer.
The leakage "is a high-risk toxic cocktail made up of substances which cause cancer and damage to the endocrine system," Simonetta Lombardo of Info-Rac told reporters.
"It is not oil that has flowed but fuel for power statioms," she said. "This contains substances such as benzene, categorised as a Class 1 carcinogen."
