MONTREAL -- Quebec provincial police said Wednesday they found a body investigators believe is that of a missing 71-year-old man connected to last week's Amber Alert case.

Sgt. Claude Denis said an autopsy will be conducted in order to determine if it is Yvon Lacasse, who hasn't been seen since his car was stolen Thursday night in Lachute, Que.

A six-year-old boy who had gone missing in Quebec with his father was found on Friday inside Lacasse's vehicle in eastern Ontario.

The father was arrested and charged with second-degree murder in the slaying of the child's mother.

Denis said police found the body in Arundel, Que., 100 kilometres northwest of Montreal, after several days of searching for the missing 71-year-old.

"All signs point to it possibly belonging to Mr. Lacasse," Denis said. "But there will be an autopsy and the body's identification has to be done to the satisfaction of the coroner."

Officers used ground forces, canine units and a helicopter to retrace the journey made by the suspect through Quebec to find Lacasse.

Denis said investigators received a tip that led them to Arundel, Que.

Police called the Amber Alert after the boy's mother was found dead last Thursday in a home in Saint-Eustache, Que.

Roughly 24 hours later, Ontario provincial police stopped Lacasse's stolen vehicle near Renfrew, Ont., and arrested the father.

The 41-year-old suspect has been charged with second-degree murder in the woman's death and is currently hospitalized in Ottawa after an alleged suicide attempt.