BP trial debate: How much oil spilled in the Gulf?

NEW ORLEANSThe focus of a trial over BP's 2010 oil spill in the Gulf of Mexico has shifted to the multibillion-dollar question of how much crude gushed from BP's blown-out well.

Lawyers for BP and the federal government began Monday presenting U.S. District Judge Carl Barbier with conflicting scientific theories to explain their different estimates.

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Government experts estimate 4.2 million barrels, or 176 million gallons, spilled into the Gulf. BP has urged Barbier to use an estimate of 2.45 million barrels, or nearly 103 million gallons, in calculating any Clean Water Act penalties.

Justice Department attorney Steven O'Rourke accused BP of "cherry-picking" data and ignoring information collected during its spill response.

BP lawyer Mike Brock said its experts based their calculations on "known data" using methods that meet industry standards.