The Gulf of Mexico oil spill has cost BP more than $1bn (£614m) in lawyers' fees, the company revealed yesterday, as it announced a further $150m charge to cover its external legal expenses for the disaster.
The legal fees, which do not include payments to BP's team of in-house lawyers working on the various cases associated with the spill, bring the company's total bill for the disaster to $42.7bn.
However, BP admits that the final cost could be far higher because the total does not include further potential claims to compensate Gulf businesses for lost earnings.
The chief executive Bob Dudley said this total amount was extremely difficult to provision for because these payments are currently mired in legal disputes.
Furthermore, BP has not accounted for the possibility that the United States courts could find the group's behaviour in relation to the oil spill to have been grossly negligent.
This is an accusation that the company strenuously denies but which could add more than $20bn to its costs if the courts rule otherwise.
Mr Dudley also revealed BP had created a separate team of "well under 50 people" to work on Gulf of Mexico-related issues, such as government relations and communications, to prevent it interfering with the everyday running of the company.
The oil spill began in April 2010, killed 11 workers, and gushed an estimated 4.9 million barrels of oil before it was capped 87 days later. "This has been going on for four years and will probably go on for years to come," Mr Dudley said.
He also waded into political debates yesterday, saying that the Government was right to push for shale gas exploration and arguing that he would prefer Scotland to remain within the UK.
"It seems absolutely right to see if there is shale... It has brought great economic advantages to North America and it seems to me to be wise at least to see if Britain could be involved," he said, adding that he does not see a role for BP in Britain's shale gas industry.
On the Scottish independence issue, he said: "We have a lot of people in Scotland. We have a lot of investments in Scotland. My personal view is that Great Britain is great and ought to stay together.
"The uncertainty around currency and things like that will be quite practical… It will undoubtedly add cost, through things like new offices," he added.
Mr Dudley also praised the Government for introducing tax breaks that have helped make mature North Sea oil fields economically viable, as "the UK as an oil province is definitely past its peak".
BP said that its profits tumbled to $2.8bn in the fourth quarter, from $3.9bn a year earlier, as weak margins on refining business slashed downstream profits from $1.4bn to just $70m.
The company was helped by strong performances from some of the businesses it hasn't sold in regions such as the North Sea, Angola and the Gulf of Mexico.
BP said that last year was one of the most successful years for exploration drilling for almost a decade, with seven discoveries in countries such as Brazil and Angola.
The company's full-year profits dropped by 22 per cent to $13.4bn, and so far it has purchased $6.8bn of the $8bn buyback programme announced last March.
Although BP's profits fell strongly, it avoided the profits warnings issued by its competitors BG and Chevron.