Murder charge over death of 91-year-old

Police have charged a 24-year-old man with the murder of a 91-year-old man, believed to be a family member, in Sydney's southwest this week.

Emergency services were called to a home on Hillview Street in Roselands about 9.55pm on Wednesday, following reports a man had been stabbed.

The body of the 91-year-old man was found at the scene where two police officers received minor chemical burns from hydrochloric acid found spread around the home.

The officers were treated by NSW Ambulance paramedics before being taken to St George Hospital for assessment and have since been released.

The 24-year-old man was arrested a short time later on nearby Phillip Street and was taken to hospital under police guard for treatment of arm and leg injuries.

He remains in hospital and has been refused bail to appear before court by way of a bedside hearing on Saturday.

Campsie Police Superintendent Sheridan Waldau told media on Thursday the 24-year-old had recently become known to police and is believed to have been related to the victim.

"We're not sure of the circumstances of exactly what happened last night," Supt Waldau said.

Detectives attached to Campsie Police Area Command, assisted by State Crime Command's Homicide Squad, commenced an investigation into the circumstances surrounding the incident under Strike Force Dorlton.

Multiple crime scenes were established and examined by specialist forensic police.