Portland police are looking into reports that an airport worker has been stealing jet fuel from JetBlue Airways in five-gallon jugs.

The company reported the theft to police this week after witnesses saw the man siphoning fuel from aircraft at the Portland Jetport into the container. The airline said they believe he has stolen at least 25 gallons in that manner, police said.

The value of the loss is about $160, but the airline did have to delay a flight for about a half-hour for what it thought was a fuel leak, a delay that cost the company more than $1,000.

Police did not release the man’s name because he has not yet been charged. The man did not work for the airline but for another airport vendor and has since been terminated, police said.

Police are not sure why the man was stealing jet fuel, but he told the airline that he was burning it for heat in his furnace.