The US government has said in a Louisiana court it is considering filing a civil complaint against BP under the Clean Water Act to claim 1,100 dollars for each barrel of oil spilled in the Gulf of Mexico.
If the US administration can prove BP engaged in gross negligence or willful misconduct leading up to the spill, the cost of each barrel spilled is tripled to 4,300 dollars.
This means BP could theoretically face fines of up to 17.6 billion dollars for the 4.1 million barrels that poured into the sea.
"At this juncture, the United States expects that it may file a civil complaint related to the Deepwater Horizon disaster under these provisions and possibly others," officials filed in court documents obtained by AFP Tuesday.
The Department of Justice is reviewing the Oil Pollution Act and Clean Water Act "and other statues in which enforcement action may be appropriate," officials wrote in a filing late Monday to federal judge Carl Barbier in New Orleans, who is overseeing the gargantuan complaints process for the disaster.
"As we have said from the beginning, we are committed to ensuring that those responsible clean up the mess they made, restore or replace the natural resources lost or injured in this tragedy, and repay every cent of taxpayer money," Justice Department spokeswoman Hannah August told AFP.
BP has already spent eight billion dollars trying to contain the disaster and has forecast that it will eventually cost the group more than 32.2 billion dollars.
An estimated 4.9 million barrels of oil gushed out of the well off the coast of Louisiana after it was ruptured by an April 20 explosion aboard BP's Deepwater Horizon drilling rig that killed 11 workers. About 800,000 barrels were siphoned to ships at the surface.
It took 87 days to stem the flow of oil into the sea and hundreds of miles of coastline from Texas to Florida were sullied, killing wildlife and devastating key local industries such as tourism and fishing.
Explore further: Pact with devil? California farmers use oil firms' water