Carbon monoxide is believed to have killed two men in a Rye Brook home Monday afternoon, according to officials.

Both of them lived in the home at 9 Maywood Ave., according to police, where family members discovered them after being unable to reach them since Saturday.

The victims were identified as Carl Persson, 85, and his 50-year-old step-grandson, Joseph Pendrack. Both were found dead in their beds in separate second-floor rooms.

The cause of death has not been officially confirmed by medical examiners, but Rye Brook Police Chief Gregory Austin says investigators believe it was carbon monoxide poisoning because they found a car with the ignition engaged and an empty tank of gas inside the home's garage.

"We believe the fumes from the car possibly, or most likely, drifted into the house, causing both people to suffocate," Austin says.