Ontario Provincial Police said a family member has been arrested and remains in custody in connection with two suspicious deaths near Brussels, east of Goderich.
Police say they were called to a home on Graham Road Wednesday afternoon to do a wellness check on the occupants.
They say officers found a woman dead inside the home and the body of a man elsewhere on the property.
OPP are awaiting the results of the autopsies but have said both deaths are considered suspicious.
The names of the deceased have not been released.
Police are asking anyone who may have witnessed suspicious activity in the area between Tuesday evening and Wednesday afternoon to contact them.
With files from the Canadian Press