Naea Moli, 34, is facing murder charges after killing her partner of 10 years in St Marys, Western Sydney.

Police allege she used an ax to inflict 'severe head wounds' on Geo Sione,35, while watching a film in his bedroom.

CCTV footage shows her having a cigarette outside the house before getting in a taxi to the police station. She then turned herself in.

Detective Inspector Jason Pietruszka described Naea's demeanor as 'calm' as she detailed the incident to cops.

Jason said:

"She was quite calm, she was lucid, and she provided the information."

"She spoke with the police freely. That information led us to the location."

Following extensive questioning, officers went to the scene where they found Geo's body lying on his bed.

The body had several severe head wounds, which officers believe were from an ax.

Speaking to news outlets, Jason said:

"They had been together for 10 years, they emigrated from New Zealand."

"This is a horrific incident. It shows what can happen, at its worst, regarding domestic violence. We encourage all victims of domestic violence to contact the police."

"We will continue to work with victims of domestic violence as best we can."

The inspector also described the scene as 'disturbing' and 'horrific' with Geo suffering extensive head injuries.

While investigating, the police learned that the couple had a history of violence in their relationship.

And court documents allege police had recently taken out an apprehended violence order against Geo.

According to the files, police had convicted Geo of assaulting Naea around a year before her killing him.

Neighbors said the couple had only moved into the apartment early this year.

They also said the pair was 'quiet' and kept to themselves. However, they would often hear the couple yelling or arguing.

Neighbor Tracey, who lives across the street, said:

"Waking up and seeing the forensic van still there and police cars and news crews pulling up. It was like, 'Oh my god, this is so real."'

"As a domestic violence survivor myself, it has left me shaken, shocked. It has hit really close to home."

"It's very, very sad. It just makes you realize that in this day and age, you just don't know what people's circumstances are. Or what happens behind closed doors."

While in court, Naea didn't apply for bail.