Russian oil producer Rosneft said on Thursday that around 15 tonnes (110 barrels) of oil spilled off from an idled pipeline on the Pacific island of Sakhalin, while local ecologists say the scale of disaster is far larger.
Rosneft said the spill occurred on Wednesday at the Ekhabi oilfield in northern Sakhalin. The company decided to burn the spilled oil to "minimise ecological damage".
Dmitry Lisitsin, an activist at a local ecological watchdog in Sakhalin, estimated the size of the spill at about 300 tonnes.
"They started to burn the spilled oil, people see massive plumes of black smoke," he said by phone from Sakhalin.
"This is a large spill, and the problem is of a systemic nature," said Vladimir Chuprov from Greenpeace.
"Unless oil companies start paying in full, they don't have the motivation to prevent spills," he said, adding that total fines for oil spills in Russia amount to only 10 billion roubles ($135.2 million) annually.
Ecological watchdog Rosprirodnadzor has evaluated the damage from another spill at a Rosneft subsidiary in June in Western Siberia at 270 million roubles, business daily Vedomosti reported.
Rosneft estimated the size of that spill at 0.5 tonnes.
"Due to dilapidated pipelines, the Russian oil industry spills around 30 million barrels of oil a year - this is 7 times higher than spilled at Deepwater Horizon," Greenpeace said.
($1 = 73.9530 roubles)
(Reporting by Vladimir Soldatkin; editing by Katya Golubkova and Jason Neely)