A man is clinging to life in hospital after being seriously burnt in a house fire in Sydney's south.
The man was burnt when the fire broke out at a granny flat at Gymea about 1.30am Sunday, police said.
The 39-year-old victim was taken to Royal North Shore Hospital in a critical condition, suffering extensive burns to his body.
Local police have established a crime scene.
The cause of the fire has not yet been determined and police are investigating.