Neighbors told local media a man, a young son and daughter lived in the house, but police wouldn't confirm the genders or ages of the bodies, The (Montreal) Gazette said. Officials said it was too early to classify it as a double homicide and suicide.
Using municipal and court records, the Gazette said records show the home belonged to a woman who left her husband in 2006 for another man amid a bitter child custody dispute.
The woman who owns the house was reportedly on her way to the scene from her home in Quebec City, the newspaper said.
The Gazette said the ex-husband had posted angry messages on Facebook Monday night.
"I swear, by my heart of a father, that my children will never be mistreated ever again, not even with the blessing of a hypocrite judge," the posting said.
Written by United Press International