A martial arts instructor has been arrested for the alleged triple murder of a South Korean family after a child and woman were found dead at a taekwondo centre in Sydney.
The 49-year-old was arrested in hospital late on Tuesday, after the woman and seven-year-old boy were found dead at the martial arts academy the young boy attended.
The body of a man, who was also a member of the family-of-three, was discovered elsewhere.
Australian police said at a press conference on Wednesday the suspect was in hospital under police guard, and was expected to be charged with three murders.
The man was being treated for apparent stab wounds to his chest, arms and stomach, according to a separate police statement.
He arrived at Westmead Hospital in Sydney's northwest just before midnight on Monday, and told officers he had been attacked in a supermarket car park, Detective Superintendent Daniel Doherty told the press on Wednesday.
On Tuesday morning, officers investigating the man's assault found the body of a 39-year-old man in the suburb of Baulkham Hills in the city's northwest, with what appeared to be multiple fatal stab wounds.
Two hours later, police found the bodies of a 41-year-old woman and seven-year-old boy at a martial arts centre in the nearby suburb of North Parramatta.
Mr Doherty said the boy regularly took taekwondo lessons in the centre where his body was found, and knew the instructor.
He had been set to attend a session on Monday, the day he was allegedly killed.
Photos on Wednesday showed crime scene investigators at the martial arts academy, which was cordoned off with police tape.
Police believe the family of three were originally from South Korea and lived in Baulkham Hills. They have contacted the country's local consulate.
"They (the woman and child) were subjected to an assault. We'll allege it was with murderous intent and they died from their injuries," Mr Doherty said.Police said it was too early in the investigation to speak about motive.