BP PLC accuses the federal government of improperly withholding thousands of scientific documents that could show how the government estimated the amount of oil that spewed from the company's Macondo well in the Gulf of Mexico in 2010.
Late Thursday, the oil company asked a federal court to require the government to turn over the documents. A federal judge in New Orleans didn't immediately rule.
The government estimates 4.9 million barrels of oil spewed from the well, but the company says earlier estimates may have been lower. BP faces penalties based on how much oil spilled.
BP argues the government can't withhold more than 10,000 documents on flow-rate issues because they concern factual issues, not policy determinations.
A Justice Department spokesman did not immediately respond to a request for comment.