Thi Kim Tran suffered an unthinkable crime. We finally know why.

While families were celebrating the start of the long weekend, Thi Kim Tran was living through the unimaginable — a cruelty so horrific that even seasoned police were left shaken.

The 45-year-old was at her Bankstown home with her two sons, aged eight and 15, on Thursday when a group of masked intruders broke in at about 10.30pm, police said.

Armed with a baseball bat, the men violently assaulted both Tran and her youngest son before dragging her into an SUV at gunpoint.

According to the Daily Telegraph, Tran was stripped naked and forced to sit between two of her attackers.

About an hour later, that SUV was found torched in Beverly Hills, about 6km away.

When fire crews extinguished the blaze, they made a devastating discovery — a body believed to be Tran's was inside.

Now, we finally know why.

Watch: Devastated family of Thi Kim Tran calls for justice. Post continues below.

Police said that, contrary to some online discourse, Tran had done nothing to deserve such a terrible fate.

Detectives believe Tran was an innocent victim targeted to get to her partner, who was allegedly involved in an organised crime group.

In an update on Tuesday, NSW Police homicide squad commander Joe Doueihi said police believe Tran was killed over her partner's "conflict" with a Victorian criminal drug manufacturing network, made up of predominantly Vietnamese males.

Tran had no knowledge of her husband's alleged criminal activities, police say. She may not have even known she was in danger.

Doueihi said the level of violence towards innocent victims was "rare and unprecedented".

"They're callous, they're brutal, and they're offences against innocent people," he said. "These organised crime groups are breaking their own code of conduct by targeting innocent women and children."

Thi Kim Tran has been remembered as a loving mother. Image: Facebook.

Doueihi alleged Tran's husband, who was interstate when she was killed, had allegedly been working for the organised crime network, which was believed to be involved in large-scale methamphetamine manufacturing.

He has not been charged over his alleged involvement with the criminal group. Doeihi said he has been assisting police in the investigation.

Victoria and NSW police are investigating the crime network.

Detectives searched a rural property in Springdallah, west of Melbourne, and found evidence it had been used as a drug lab.

No arrests have been made.

A 'horrendous' crime.

The eight-year-old boy remains in an induced coma. He was expected to come out of the coma on Tuesday, but could suffer lifelong implications from the extent of his injuries.

His 15-year-old brother was also taken to hospital for assessment. Doueihi said he suffered severe "psychological injury".

The severity of the crime has shocked authorities at all levels.

Tran had left work on Thursday and headed home to prepare for a trip to the Royal Easter Show and the long weekend, colleagues told The Daily Telegraph.

Just hours later, she was dead.

Superintendent Rodney Hart said the body in the car was so badly burned that visual identification was impossible. But police strongly believe it was the 45-year-old mother.

Authorities are yet to rule out whether Tran was burned alive.

"This crime is horrendous, the level of violence is unheard of," Hart said. "But I want to reassure the community we strongly believe this is a targeted incident and this has not been a random kidnapping."

Police at a crime scene involving a burnt-out car in Beverley Hills. Image: AAP.

A close friend of Tran's told the Sydney Morning Herald she was shattered by the news, describing Tran as someone who was "always happy to see her friends and share meals".

Tran's family had already endured tragedy, grieving a death just last year.

"This is so awful … She didn't deserve this," she said. "She was a loving mother ... Everyone is in shock."

Authorities are trying to reach Tran's family in Vietnam, who must now pick up the pieces from afar as they wait for answers — and justice.

Detectives are facing a complex investigation as they work to identify those involved.

Hart vowed to do the best for Tran's children and get justice for her family.

Police are are appealing anyone with relevant information or video footage to come forward.

Investigations are ongoing.

Featured image: Facebook.