"BP is in the process of shutting in a well at the Prudhoe Bay oil field that experienced an unplanned release of hydrocarbon", said Brett Clanton, a BP spokesman in Houston.
In an emailed statement, BP said the well, located at the Prudhoe Bay oil field on Alaska's North Slope, began to leak Friday.
An oil well leaking natural gas on Alaska's North Slope has been successfully plugged, according to private and government responders.
By looking at the aerial pictures that were released by the department, it seems that the release is under control and contained to the gravel pad only, which surrounds the head of the well.
The Alaska Department of Environmental Conservation says the spill is ongoing and the volume is unknown.
But the platform is still venting gas from a leak associated with a damaged pressure gauge.
EPA chief: Agency to reconsider methane emissions rule
But an EPA official told CNN the initial report saying the agency is considering shutting down the Chicago office is false. O'Grady said buyouts and early retirements won't achieve that goal, because the math makes it unrealistic.
Media covering the accident recall that this is not the first spill for BP's Alaskan operations, which account for over half of the state's oil and gas output.
North Slope production rose to 565,000 barrels a day in March, its highest level since December 2013.
The BP leak comes on the heels of pipeline leaks in Alaska's Cook Inlet off Anchorage. The Coastal Plain of the Arctic National Wildlife Refuge also contains vast reserves of oil - as much as 16 billion recoverable barrels, by some estimates. Fox News is reporting there are actually two leaks - one near the top and one further down the well assembly, says BP.
There were no reports of harm to nature or injuries.
But the release of vented natural gas means that the well is still leaking methane, a potent greenhouse gas that traps heat 86 times more effectively than carbon dioxide over a 20-year period, into the atmosphere.
In a 2011 settlement with the Department of Justice, BP agreed to pay a $25 million civil penalty and carry out a "system-wide integrity management program" after it spilled more than 5,000 barrels of crude oil from its pipelines on Alaska's North Slope in 2006.