Detectives from the Arson and Explosives Squad are investigating following a suspicious house fire in Clyde North.
Emergency services responded to reports of the fire and people injured at the Sunburnt Circuit property about 1.45am on 18 December.
Two men aged 46 and 44 were taken to hospital with life-threatening injuries.
A 29-year-old woman was transported by road to hospital with non-life-threatening injuries and was under police guard.
A 43-year-old woman and a 12-year-old child who were also inside the property at the time of the fire were not physically injured.
A crime scene has been established and the investigation into the circumstances surrounding the incident remains ongoing.
Anyone who witnessed the incident, has dashcam or CCTV footage or anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit an online confidential report at www.crimestoppersvic.com.au
