Donna Graves, 61, and her son Daron Graves, 29, were last heard from as they left The Prior Sports Bar and Restaurant in Arnprior, Ont., at 11 p.m. Thursday.
West division Staff Sgt. Patrick McCaffery said the vehicle matches the description of the Black 2013 Dodge Dart belonging to the Graves family.
McCaffery said one deceased person was located in the car but they have not been able to positively identify the victim.
Police began investigating the river close to Graves's Ferry Road home when they saw skid marks on the road and debris left behind, suggesting a vehicle struck the wharf and was in the river.
Dive teams located a car in the river Saturday night. Police at the scene said they are treating the incident as a car accident and said speed may have been a factor in the crash. The vehicle had rolled over and was upside down about 25 feet underwater and about 40 metres from the jetty.
Divers were scheduled to return to the water at 11 a.m. Channels will have to be cut into the ice to allow for cables to attach to the car, and then more ice will need to be cut to allow a crane to lift the vehicle out of the water, said McCaffery.
McCaffery said conditions at the site of the crash are proving challenging, as the temperature is dropping. At 10 a.m. it was 0 degrees C, but was expected to drop to -13 later Sunday afternoon.
The coroner will not be at the scene until the car and body are removed, police said.
Grief counsellors at home
Grief counsellors are also at the Graves home on Ferry Road, within sight of the recovery operation.
David Graves, Donna's husband and Daron's father, said his wife had called him Thursday night and said they were on their way home, but they failed to show up.
Graves said his family was planning to have a dinner party Friday night, so his wife went to Arnprior to pick up some groceries. Daron went with her and drove, and was planning to go pick up some work gloves.
The two decided to eat and play some pool at The Prior, which Graves said was not an unusual circumstance. He said his wife was gregarious and that she and their children socialized as peers.
Graves said his wife called at 11 p.m. and said they were leaving the bar and would be home soon. He said he doesn't believe they drank too much, and said it was understood that if someone needed a ride home, he would come and pick them up.
Graves said he spent Friday driving the routes he believed his son might have taken to get home.