New federal research has found that a 15-year-old oil leak in the Gulf of Mexico has been releasing as much as 4,500 gallons per day.

A wrecked platform has been leaking as much as 4,500 gallons per day of crude oil into the Gulf of Mexico since 2004, not three or four gallons the rig proprietor has claimed in the past, according to a U.S. National Oceanic and Atmospheric Administration (NOAA) study released this month.

The platform owned by Taylor Energy collapsed and sank in September 2004 during the widespread damage caused by Hurricane Ivan in the Caribbean and the United States (U.S.) and, 15 years later, oil keeps leaking into the sea in a major spill much bigger than anticipated.

As much as 4,500 gallons per day could be leaking out from the site according to the study that has been conducted in collaboration with researchers from Florida State University and Florida International University. Satellite imagery has shown slicks on the surface of the water, sometimes ranging up to 30 km in length.

In the meantime, Taylor Energy says that slicks on the surface of the water only indicate that two to four gallons are seeping out. "The results of this study contradict these conclusions," scientists wrote in the report.

Various studies had already come to contradict the numbers presented by the company over the past years. Last year, for instance, an independent study refuted the energy company’s figures showing that even more oil (70,000 gallons a day) could be pouring out of the site, while other reports have said it could be between 9,000 and 25,000, according to Associated Press.

A federally led study shows a 14-yr #oilspill is leaking up to 4,500 gallons a day. #Oil and #gas have been leaking into the Gulf of Mexico since a subsea mudslide chopped down #TaylorEnergy’s oil platform in 2004 burying the broken wells under more than 100 ft of sediment. — NYSBA Env & Energy (@NYSBAEELS) June 27, 2019

The new report also recalls that the rig's structure came to rest on the ocean floor and the collector bundle containing the original 28 pipes were buried by deposited sediment after breaking off. Taylor Energy has sealed some of the leaks, but said that the buried rest couldn’t be displaced without risk of environmental harm.

The leakage was discovered by scientists in 2010 and no coastal environmental damage nor dying wildlife were witnessed from the seepage at that time, driving some scientists to call it a "hidden oil spill."

“This is an unresolved, ongoing leak 14 years later,” Daniel Jacobs, author of a book following BP's oil spill and professor at Loyola Marymount University stated, adding that “this is one more indication that we’re not able to increase offshore drilling.”

The NOAA team measured output at the Taylor platform leaks for a six-day period last September, and it said that their results should serve to measure the total amount leaked from the platform over the past 14 years. They said the numbers will be used along with further studies and that they will continue to investigate the leak.

The continuing release of oil is happening where the waters of the Mississippi River and Gulf of Mexico mix. These large slicks can have detrimental repercussion on rich marine resources including plankton, fish and invertebrates (especially the sensitive early life stages), sargassum, birds, mammals and turtles.

Some 330,000 gallons of oil make their way into the Gulf of Mexico every year, according to a state agency that monitors spills.