A double murder probe was launched after two bodies were found following a house fire.
Firefighters made the discovery at Fort Mead Close, Barnstaple, yesterday morning, Devon and Cornwall Police said.
An injured man was rescued from the house and taken to North Devon District Hospital where he remained today.
Supt Richard Baker, of Devon and Cornwall Police, said: "This is a very early stage in the police inquiry and we are still trying to piece together the series of events which preceded this tragedy.
"We are still in the process of identifying the two bodies, how they came to be there and notifying the two deceased's next-of-kin.
"This is a very unusual incident and we appreciate that the local residents have concerns."
A cordon remained at the scene today.
No arrests have been made.
Neighbour Josephine Palmer, 84, said: "My carer called the fire brigade because she saw smoke coming from the house. It was at about 9am and they were with us within five minutes. It was very impressive.
"I don't know who the people are though - neighbours aren't what they used to be."
Witnesses are asked to contact police on 08452 777444 quoting log 404 220810. Anyone with any information is requested to ring the same number quoting crime reference 1014.10 or contact Crimestoppers on 0800 555111.