Log rolls out of fire sparking massive house blaze

A man's in hospital with serious burns after a log rolled of an ole fire engulfing his home south-east of Melbourne.

The blaze broke out around 3am at the weatherboard home on Main South Road in Drouin.

Investigators said a neighbour alerted emergency services and when police and fire crews arrived they located a man at the back of the home.

Police say he was suffering severe burns to his lower body and smoke inhalation.

At this stage fire investigators believe the blaze started after a log rolled off an open fire igniting contents of home before it spread.

The man was stabilised at the scene by paramedics before being flown to the Alfred Hospital in Melbourne.

He was the only person inside the home at the time.

"I suppose it doesn't get any worse," Sargent Dean Waddell told 9NEWS.

Officials remain at the property as they complete their investigation.