A man's body has been discovered in a burned out house in northwest NSW after firefighters battled a blaze at the property for more than two hours.

Emergency services were called to the home in Euroka Street, Walgett at about 5.30am (AEDT) on Saturday following reports of a fire.

Human remains were found in the property after the blaze was finally extinguished at about 8am.

Police believe the body is that of a 69-year-old man.

Investigators have established a crime scene but are yet to determine the cause of the fire.

They have urged anyone with information about unusual or suspicious activity in the area to come forward.

The body will undergo a post mortem examination and a report will be prepared for the coroner.