The provincial fire marshal and police are investigating after a man’s body was found inside a burnt-out barn in La Nation, Ont., about 70 kilometres east of downtown Ottawa.

Hawkesbury OPP said they were called to a barn fire on Leroux Road just before 7 p.m. on Monday.

Police said it is not known why the small barn caught fire. Once the blaze was under control, a man's body was found on the scene.

Police do not suspect foul play, but they have not yet ruled it out.

Homeowner’s oldest son killed

Albert Picard said his oldest son, who was in his 20s, was the one killed in the fire.

However, Picard said he doesn’t know why his son was inside.

Neighbour Cody Devine-Cayer said the area was "swarmed" by more than a dozen fire trucks.

"I saw that the barn was on fire and I saw it spreading to a bit of the grass and backyard," he said.

"I heard a few bangs, I was wondering what would make that sound."

The OPP identification and crime units, as well as the coroner’s and fire marshal’s offices, are expected to work on the case for the next two days.

"We're not suspecting foul play, but we sift through all the debris to make sure no criminal acts were committed," said OPP Const. Pierre Dubois, adding they want to know the cause of the fire.