BATON ROUGE, Louisiana - A U.S. senator from Florida is pressing federal officials to disclose technical data and other information about a decade-old oil leak in the Gulf of Mexico, after an investigation by The Associated Press revealed evidence that the spill is far worse than a company or government regulators have publicly reported.

In a letter Friday to Interior Secretary Sally Jewell and Department of Homeland Security Secretary Jeh Johnson, Sen. Bill Nelson said it is "unacceptable" that oil is still leaking from the site off Louisiana's coast where an oil platform owned by Taylor Energy Company toppled during Hurricane Ivan in 2004.

The Florida Democrat, who is the ranking member of the Senate Committee on Commerce, Science & Transportation, told Jewell and Johnson that "all necessary resources" should be committed to stopping the oil from flowing.

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"If you've got an oil rig that's been leaking for 11 years, then it's time for us to find out what's going on," Nelson said during a telephone interview.

Taylor has downplayed the leak's extent and environmental impact. The New Orleans-based company recently touted a year-old estimate that less than 4 gallons (15 liters) per day is spilling at the site where its cluster of 28 wells remain buried under sediment from a mudslide triggered by Ivan's waves.

But the Coast Guard provided AP with a new leak estimate that is about 20 times greater than the one cited by Taylor.

AP's analysis of more than 2,300 pollution reports to the Coast Guard since 2008 showed a dramatic spike in sheen sizes and oil volumes since Sept. 1, 2014. That came just after federal regulators held a workshop to improve the accuracy of slick estimates reported by a Taylor contractor and started sending government observers on monitoring flights over the site.

When presented by AP with evidence of the spike, the Coast Guard attributed it to an improved method for estimating the slicks from the air - with the clear implication that far more oil had been spilling for years than had been reported.

After BP's massive Gulf oil spill in 2010, Nelson criticized the London-based oil giant's reluctance to publicly release videos of its underwater gusher. BP eventually broadcast a live video feed that showed its efforts to stop the spill, which dwarfed even the highest estimate of Taylor's leak.