Police are investigating whether an axe was used in a dispute that left two people dead in Cartwright this afternoon.

Key points: Police were called to the Cartwright apartment following a neighbourhood dispute

Police were called to the Cartwright apartment following a neighbourhood dispute A man and a woman were critically injured with stab wounds and both died shortly afterward

A man and a woman were critically injured with stab wounds and both died shortly afterward A second man was taken into custody

Police were called to the apartment complex just after 4:00pm and found the man and a woman suffering serious stab wounds.

The man was treated by paramedics at the scene but could not be saved.

The woman was taken to Liverpool Hospital in a critical condition but died a short time later.

A suspect was arrested at the Huntley Street address and taken to Liverpool Police Station.

Superintendent Adam White of Liverpool City Police Area Command said the officers had declared a crime scene.

Police are investigating whether an axe was used in the attack in Sydney's southwest. ( ABC News )

"It appears a male and a female have come to the units here in Cartwright in respect to a dispute and as a result of that a scuffle has broken out," he said.

"Unfortunately it has resulted in two people being seriously injured and passing away from those injuries."

Superintendent White said several items were taken from the scene.

"It appears to be a specific attack, it's not random," he said.

Local Vilay Khammana said he was "shocked to hear" of the attack taking place in what he described as a "quiet area".

"My grandma lives just across the road from here, [near] where the stabbing happened," he said.

"I don't feel safe at all."