Two people are dead and a man is in custody after a stabbing in north-west Sydney this morning.
Just before 5am, emergency services were called to a home in Illabo Street in Quakers Hill after reports of a disturbance.
Police found a man, believed to be aged in his 30s, on the footpath who had suffered apparent stab wounds to his stomach and hands.
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A woman was found dead inside the home. She is yet to be formally identified but is believed to be aged in her 30s.
The man was taken to Liverpool Hospital in a critical condition, but he died from his injuries later this morning.
Superintendent Jason Joyce said the scene was challenging for police and paramedics.
"It was a very traumatic incident," he said.
"Very sad in terms of the time of the year, my sympathy goes out to the family of the deceased.
"Very confronting for my police and emergency services that attended. Obviously not a nice thing to see."
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Police believe the two people who died were in a relationship.
A 47-year-old man was arrested after he attended Blacktown Police Station at about 5.30am.
Joyce said the suspect could face murder charges.
"The male that's in custody was previously in a relationship with the female," Joyce said, adding police believed the incident was domestic violence-related.
Multiple crime scenes have been declared, including at the Illabo Street home and at a service station in Woodcroft, where a knife used in the alleged attack was located.
A crime scene has also been declared at a home in Blacktown, where the suspect lives, and at Liverpool Hospital.
Police have urged any witnesses or anyone with CCTV or dashcam footage between 4.30am and 5.30am to contact Crime Stoppers.
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