Crews are cleaning up a significant oil spill near the Hudson River in Tarrytown.

Police say they began getting calls around 11 p.m. Wednesday about a strong smell of fuel coming from a brook that runs along the Hudson Harbor Complex across from the Tarrytown Metro-North train station.

An oily sheen could be seen on top of the water in the spillway, and Tarrytown firefighters put booms in the water to block the oil from going into the Hudson River. They say the red color of the fuel seems to indicate that the substance is heating oil.

DEC officials also responded to the spill, which it says is no longer active or a threat to the wildlife.

Investigators will try to determine what caused the sheen to develop.

"We don't want any environmental issues. It's just we have to see who got fuel deliveries in the past and go from there," says Tarrytown Deputy Fire Chief Patrick Derivan.