BP is expected to face a fine of up to $13.7bn after a US judge ruled that the company discharged 3.19 million barrels of oil into the Gulf of Mexico in 2010.

The government calculated the spill size to be 4.2 million-barrel, but this was rejected by the US district court in Louisiana.

"BP has to-date paid more than $42bn for the disaster, which killed 11 people."

The finding precedes the third phase of trial, which will determine BP’s Clean Water Act penalties.

BP has to-date paid more than $42bn for the disaster, which killed 11 people and spread oil across seafood grounds and coastal beaches.

BP spokesman Geoff Morrell was quoted by Bloomberg as saying the company does not believe it deserves the maximum Clean Water Act fine.

"BP believes that considering all the statutory penalty factors together weighs in favour of a penalty at the lower end of the statutory range."

The company is continuing to review the court’s decision.

In September 2014, US District Judge Carl Barbier ruled that BP cannot recoup the additional money paid out under the old accounting method.

The British oil and gas firm paid hundreds of millions of dollars to the alleged victims of the spill through multiple businesses between August 2012 and October 2013.