The U.S. government could fine BP up to $4,300 for every barrel of oil gushing into the Gulf of Mexico -- a provision in federal law that some lawmakers are citing in their efforts to keep precise record of the spill's magnitude.

Reuters reported Wednesday that a clause within the U.S. Clean Water Act may expose BP and others to civil fines that are not limited to any finite cap.

The Act permits the government to seek civil penalties in court for every barrel of oil that spills into U.S. waters, according to Reuters.

Sen. Bill Nelson, D-Fla., and other lawmakers are highlighting the clause in their push to quantify the barrels of crude oil leaking into the ocean. An aide to Nelson told FoxNews.com Wednesday that the senator is pressing for BP to release more video footage showing the oil leaking from the well.

The environmental group Sierra Club estimates that the April 20 explosion at Deepwater Horizon has released more than 1,444,952 barrels into the Gulf as of midday Wednesday. By that estimate, BP would owe more than $6.2 trillion in fines so far if the federal government imposes a $4,300 penalty per barrel.

Fox News' Trish Turner contributed to this report