Police are investigating a suspicious house fire at a First Nation reserve after a person suffered life-threatening injuries early Thursday morning.

The Ontario Provincial Police and Tyendinaga Police say they were called to a structure fire on Old Highway 2 in Tyendinaga Mohawk Territory shortly before 4 a.m.

The First Nation reserve is about 24 kilometres west of Greater Napanee.

Three people escaped from the home uninjured. A fourth person was removed by firefighters and taken to hospital with life-threatening injuries.

An investigation into the fire is ongoing in conjunction with the Office of the Fire Marshal and under the direction of the OPP Criminal Investigation Branch

Investigators are looking to speak with anyone who has doorbell, dashcam or other video recordings around the area along Old Highway 2 from Dec. 6 to Dec. 7.

Anyone with information should contact OPP at 1-888-310-1122.

Those wishing to remain anonymous can contact Crime Stoppers at 1-800-222-8477 or contact Crime Stoppers, where you may be eligible to receive a cash reward of up to $2000.