Norilsk Nickel, which is the world's leading producer of nickel and palladium, has not paid "not one rouble" in damages, according to Rosprirodnadzor.
"To date, the company has not paid a single rouble in damages, and the amount the company intends to pay has also not yet been named," the agency said in a statement on Thursday.
Rosprirodnadzor added that it hoped the mining company was not trying to delay the payment of the fine.
"The physical elimination of the negative environmental impact [of the spill] and damage payment claims are quite different in nature," the agency said.
Rosprirodnadzor recently assessed the damage at 148 billion roubles (approximately $2.07 billion) – a record fine for Russia – and sent Norilsk Nickel a claim demanding voluntary compensation.
Norilsk Nickel CEO Vladimir Potanin responded by saying his company intends to challenge the claim, later adding that he was "willing to discuss the assessment with the authorities."
The mining giant recently outlined its clean-up strategy for the region affected by the spill. Russia's Civic Chamber said it had multiple issues with the document, adding that a list of objections will be presented to the government no later than September 1.
A fuel tank collapsed at a combined heat and power plant (CHP) near the city of Norilsk on May 29, resulting in the spill of close to 21,000 metric tons of diesel into the ground surrounding the facility and several major rivers in the area, leading to a federal-level state of emergency and multiple criminal cases being opened against the company's employees and the mayor of Norilsk.
The plant is owned by the Norilsk-Taimyr Energy Company (NTEC), which manages the energy assets of Norilsk Nickel in the Krasnoyarsk region. Norilsk Nickel CEO Vladimir Potanin has vowed to clean up the pollution at the company's expense.
Rosprirodnadzor reported that 6 thousand tons of diesel contaminated the ground, while the remaining 15 thousand tons ended up in the region's water bodies, polluting the Ambarnaya and Daldykan rivers, as well as almost all their tributaries. The total area of the spill was assessed at 180 thousand square meters.
The spill is the second-largest in Russian history, following a 1994 accident in which an estimated 100,000 tons of oil burst into the tundra from a ruptured pipeline between Usinsk and Kharyaga.