The source of a fire that gutted half a duplex and left its tenants grieving over the loss of pets and all their possessions on Sunday will remain a mystery.

At around 1:30 p.m., neighbours phoned Kamloops Fire Rescue to report smoke billowing out of the Fernie Road property in the City's West End.

The property was empty at the time except for a dog, two cats and a rabbit. Only the dog escaped.

Some said they heard an explosion before noticing the fumes. But on Tuesday, Kamloops fire investigators concluded their inspection and it revealed very little, said investigator Arlene Ball.

"The cause of the fire will remain undetermined," she said.

Authorities determined that the point of origin was in the middle of the living room. But there was no evidence of a source, she said.

Chances are insurance investigators will hold their own examination before paying out the claim. But private inspections often reach the same conclusions as official probes, said Ball.

Meanwhile, the couple renting the home is now financially strapped and living in a motel, according to their friend Bruno Ariganello.

Ball said the victims had turned down her offer for emergency social services assistance, which would have provided 72 hours of food and shelter.

The pair was reached but declined to provide their names to media.