A 31-year-old man, husband and father Aaron Holloway, survived the blaze by escaping through the front door of the home at Clifton Springs, south-west of Melbourne.

The truck mechanic underwent surgery in Geelong Hospital after receiving burns, abrasions and smoke inhalation, and is in a stable condition.

It is believed his wife Ashleigh and their children Brodie, 212, Thomas, 18 months, and three-month-old twins McKenzie and Cooper all perished.

Firefighters who arrived at the Jetty Road weatherboard home at about 2.30am found the property engulfed in a fire that was fanned by fierce winds.

Victoria Police confirmed at 3.20pm that five bodies had been found.

''We can confirm that five bodies have been located, including four small children,'' a police spokeswoman said.

The fire completely destroyed the home and severely damaged a neighbouring property.

Mr Holloway's mother said outside Geelong Hospital that her son was ''hurt and in pain''.

Jetty Road resident Alfred Terrill, 72, said he was woken at about 2am by a woman screaming. The woman, a passer-by, had stopped her car and was screaming at the occupants inside, trying to rouse them, Mr Terrill said.

He said he looked out the window after hearing the screams and saw flames completely obscuring the house. ''It was a wall of flame from one end [of the house] to the other,'' Mr Terrill said. ''I couldn't even see the house for the flames, just a red wall of fire.''

The fire quickly spread to a neighbouring house, forcing its occupants to flee, while an ember set the roof of a third property alight.

Police said they could not confirm ages or genders because the bodies had not been formally identified. Disaster victims identification experts have been called in.

The arson squad's Detective Sergeant John Dimos said, ''At this early stage, we don't have a cause of the fire but that is still being determined by our investigators.''

Police interviewed Mr Holloway yesterday.

The Victorian coroner is also investigating. AAP