The fire that destroyed a building on Six Nations territory in Brantford is being investigated as suspicious.

Fire broke out Sunday evening at the building at 291 Mohawk Street. The house was engulfed in flames before firefighters arrived at the scene.

Crews needed more than three hours to knock the fire down – and even then they couldn’t get inside to search for victims, as the fire had caused a partial roof collapse and made the home unsafe to enter.

Six Nations authorities were called to the scene as well, once authorities realized that the property in question is considered Six Nations territory.

The building where the fire broke out is next to Her Majesty’s Royal Chapel of the Mohawks, which was built in 1785 and is believed to be the oldest church in Ontario that is still in existence.

Six Nations fire chief Matt Miller says the location and nature of the fire is concerning.

"The Mohawk Chapel is adjacent to this structure, is actually the oldest church in all of Ontario, so it's a pretty significant landmark. It's also very significant to the Six Nations of The Grand River territory in many ways. So we're very glad the fire didn't spread to that structure," Miller said.

He credits Brantford fire crews for knocking down the flames quickly.

Authorities from Brantford, Six Nations and the Office of the Fire Marshal are now investigating the fire.