Sri Lanka on Friday lodged a claim for $17.38 million with the Greek owners of an oil tanker that caught fire and left a spill stretching 40 kilometres (25 miles) off the South Asian island.
The New Diamond vessel was travelling from Kuwait to India with 270,000 tonnes of crude oil on board in September when a fire broke out as it passed Sri Lanka's east coast.
The crude being carried as cargo was unaffected by the blaze but some of the tanker's fuel leaked into the Indian Ocean.
Its skipper was in October fined $65,000 for causing the spill and failing to inform local officials of the environmental damage left behind.
Authorities are now seeking compensation from Greek firm Porto Emporios Shipping Inc for the damage.
"The Attorney-General forwarded the marine pollution claim for 3,423 million rupees ($17.38 million) to lawyers of the owners of MT New Diamond in respect of the oil spill caused in September," the office of Sri Lanka's state prosecutor said in a statement.
Officials said about 400 to 480 tonnes of fuel had leaked from the Panamanian-registered ship.
Firefighters led by India's coastguard as well as the Indian and Sri Lankan navies succeeded in putting out the blaze before the vessel was towed to the United Arab Emirates.
Porto Emporios paid Sri Lanka $2.38 million for extinguishing the fire.
The blaze started after an engine room boiler exploded, killing one crew member. The remaining crew of 22, including the skipper, were rescued.