A pet rabbit is credited with saving a couple from a fire that swept through their home in the southern city of Melbourne.

Metropolitan Fire Brigade commander Mick Swift said the husband returned home from a night shift early Thursday and heard the family pet, named "Rabbit," scratching at the couple's bedroom door half an hour after he had gone to bed.

Swift said the husband, whose identity has not been released, discovered a fire in a back room and smoke spreading quickly through the house. He was able to escape the house with his wife unharmed.

Swift said the rabbit saved the couple from injury.

He said the blaze caused substantial damage to the house before it was extinguished by four crews of firefighters.