A fourth person has died following a violent weekend in the Chaudiere-Appalaches region west of Quebec City.

11-year-old Beatrice Godin had been in critical condition since Saturday night and died of her injuries Wednesday morning.

On Saturday Beatrice's mother Nancy Samson, 44, and her boyfriend Benoit Daigle, 39, were killed outside their home in Sainte Croix.

Clues at the scene prompted police to rush to the home of Samson's ex-husband in nearby St. Isidore.

There, police discovered Beatrice's sister, 13-year-old Medora Godin, who was pronounced dead at the scene.

Their father, Martin Godin, 54, and Beatrice were both unconscious and rushed to hospital.

Martin Godin remains in critical condition and is considered the prime suspect in the four murders.

Autopsies were performed Monday on the older Godin sister and the two other victims but the exact cause of death has yet to be released.