A subsidiary of BP is reporting a crude oil spill on Alaska's North Slope.

BP Exploration Alaska Inc. told state regulators Friday that oil is spraying from a well onto a pad and possibly onto the snow-covered tundra, reports UNB.

The Alaska Department of Environmental Conservation says the spill is ongoing and the volume is unknown.

BP employees discovered an uncontrolled natural gas leak that was accompanied by the spray of crude oil.

BP and state regulators are investigating the cause.

State officials say a clean-up will begin once the release has been controlled.