A NSW man has suffered extensive burns to his body in a fire at a property in Gymea in Sydney's south.
The 39-year-old was found after emergency services were called to a fire at a granny flat at about 1.30am Saturday.
The man, who was trapped inside the unit as the fire quickly spread, was taken to Royal North Shore Hospital in a critical condition.
NSW Ambulance Inspector Greg Price said the man suffered burns to 70 per cent of his body which included "full and partial thickness burns".
Fire crews managed to put out the fire, but the property was destroyed.
Police are questioning a woman as they investigate the cause of the fire.