Toronto police have charged a man and his wife with elder abuse after a 68-year-old woman was found in medical distress in a non-insulated garage, where she had allegedly been housed during the winter.

Senior officers described the case as "disturbing."

"This is one of the worst I have ever seen," Toronto police Det. Sgt. Mike Stones told reporters on Monday, as he described the allegations against the woman's son and daughter-in-law.

The hospitalized woman remained in critical condition, hooked up to oxygen and feeding tubes on Monday, nearly a week after paramedics were called to a home in the McCowan Road and Finch Avenue East area in Scarborough.

Police said they received a call last Wednesday from paramedics who had been called to assist an unconscious woman inside the garage. The woman was suffering frostbite to her toes.

She had allegedly been living in the garage since November 2010.

Stones said police believe the garage had been retrofitted into a makeshift bedroom, with two drywall walls erected to form a room next to the cinderblock exterior walls.

The room had no fridge or other amenities other than a bucket of water used as a wash basin. A port-a-potty was found in the garage, but it was not being properly maintained, police said.

The garage was heated by a modified dryer vent that had a maximum temperature 20 degrees below the interior of the house.

Police also allege the woman was not provided with adequate food. Her stomach was empty when she arrived at the hospital, Stones said.

Stones said the woman had been declared legally incompetent in the fall of 2010 and placed under her son's care.

The couple, with a seven-year-old daughter, lived inside the home with two tenants. Two bedrooms sat empty inside the house, one of which had direct access to a bathroom.

The family was originally from mainland China but are now Canadian citizens, Stones said.

On Friday, police arrested Kwong Yan, 43, and Qi Tan, 28, and charged them with failing to provide the necessities of life, as well as criminal negligence causing bodily harm.