A homicide investigation is underway after a man was found dead with extensive burns outside his western Sydney home, with police alleging his son set him on fire following an altercation. Emergency services were called to Wargon Crescent in Glenmore Park shortly before 1 a.m. on Thursday, responding to reports of a fire. Upon arrival, they discovered the body of a man in his 60s, suffering from multiple severe injuries, including significant burns, outside his partially alight home.

Detectives arrested a 36-year-old man approximately five hours later. Police sources confirmed the arrested man is the son of the alleged victim, though he did not reside at the Glenmore Park address. Superintendent Trent King of St Marys police stated that an altercation appeared to have occurred between the two men, following a break-in where the front door was forced.

"An accelerant appears to have been used," Superintendent King said, noting that the exact sequence of events within the premises is still under investigation. He described the scene as "really distressing" and "not a normal scene for anybody to be confronted with; particularly the extent of the injuries to our victim."

The 36-year-old suspect has a criminal history and is known to police. Superintendent King clarified that there is no history of domestic violence between the father and son. A post-mortem examination will be conducted to officially determine the cause of death.

The fire, which started in a blue Commodore in the driveway and spread to a portion of the house, was extinguished by Fire and Rescue NSW. There was no structural damage to the home. Police and forensic officers remained at the cordoned-off Glenmore Park residence throughout Thursday.

A second crime scene was established in Werrington, where the younger man was apprehended without incident. He was taken to Nepean Hospital for treatment of minor injuries to his feet and hands and remains under police guard. "We’re very early in the investigation," Superintendent King added. "We believe the injuries may be the result of the interaction between the two parties."

Strike Force Dorinu has been formed by detectives, with assistance from the State Crime Command Homicide Squad, to investigate the death. Police are appealing for information, CCTV, or dashcam footage related to the incident, urging anyone with details to contact Crimestoppers on 1800 333 000.