A man who was arrested over the suspicious death of his mother at their townhouse in Sydney's south early on Monday morning was found carrying a crossbow in his vehicle when he was stopped by police, police say.
The 31-year-old man was arrested on the Princes Highway at St Peters following the death of his 55-year-old mother in Sylvania.
Superintendent Michael O'Toole said the woman's other son, aged 28, called police about 6.45am on Monday after finding his mother dead in her bed inside the Florida Street townhouse where all three lived.
It is understood the woman was found wrapped in a blanket with a significant head injury and covered in blood.
Superintendent O'Toole said that, several hours after the woman's body was found, police pulled over her older son.
He was arrested and taken to Newtown police station, where he was being questioned over his mother's death. No charges had been laid on Monday morning.
"There was a crossbow taken out of the vehicle, but there are other items [that have] also been taken out of the vehicle that the older son was in," Superintendent O'Toole said.
He said it was not yet clear whether any weapons were used in the woman's death.
Superintendent O'Toole said the younger son was "very distraught" about what had happened.
"He is the one who came across the incident and called police to attend," he said.
Detectives have set up a crime scene at the townhouse complex, and are speaking to neighbours.