Daniel Merrett was killed instantly and passengers Kayleen Merrett, Jakaya Clulow and Thomas Johnson were seriously injured when their Ford Territory slammed into the truck on the Princes Highway in the early hours of May 18.

The trio had allegedly been trying to flee at the time from a silver Toyota Corolla containing Darren Butler, Andrew Russell and Holly Green, who claimed Mr Johnson owed them money and became irate when he wouldn't pay.

Court documents reveal Mr Johnson owed Green's brother $150 and about a week before the crash had sent him a message indicating he'd inherited some money from his grandfather.

Mr Johnson was with Mr Merrett, Ms Merrett and Clulow getting petrol at the Cringila Service Station in the early hours of May 18 when Butler, Russell and Green pulled up beside them. Butler allegedly told Johnson "you owe us $2000", which Johnson initially disputed, but subsequently attempted to transfer into Butler's bank account.

The transfer was unsuccessful and Mr Johnson left the service station with his friends, travelling to a house in Wegit Way, Warrawong.

It is alleged Butler, Russell and Green followed in the Corolla, pulling up alongside the Territory as Russell brandished a rifle out the window and again demanded payment.

The Territory took off, travelling west on Northcliffe Drive. Mr Johnson later told police from his hospital bed that he heard two gunshots behind them as they drove at speed towards the highway, with the Corolla very close behind them.

Meanwhile, Mr Merrett contacted Triple 0, telling the operator they were being chased and shot at while driving along Northcliffe Drive. He could be heard yelling the name "Kaylene" and telling her to accelerate, police said.

"They have a loaded gun and they have just shot at us ... they have just shot the side of our car," Mr Merrett told the operator.

When asked who was shooting at them, Mr Merrett replied "Darren Butler, Brothers For Life".

Court documents said Mr Merrett is heard telling the operator their whereabouts as they passed the Dapto Showgrounds, then Yallah and Haywards Bay.

"About one minute later, screams were heard immediately prior to the sound of a loud bang," police said in documents tendered to the court.

CCTV footage taken from a house opposite the crash site showed the Territory slam into the fuel tanker at an estimated speed of about 160km/h.

Mr Merrett was ejected from the car through the windscreen and died on impact.

The CCTV footage allegedly shows the silver Corolla veer around the crash site and continue south along the highway moments after the crash.

Mr Johnson, Ms Merrett and Ms Clulow were taken to hospital while police began an investigation into the crash.

Detectives issued warrants for the arrests of Butler, Russell and Green three days later.

Russell was apprehended on May 22, while Butler was arrested on May 30.

Police will allege Butler was aided while on the run from police by his girlfriend of seven weeks, Holy Powers, and another friend, Matthew Ryan.

A tap on Powers' mobile phone allegedly picked up a call from Butler on the morning of May 30 where he asked Powers for money for petrol.

Powers arranged to meet Butler at Westfield Figtree that morning. Butler and Ryan arrived in a Nissan Navara owned by Ryan and they picked up Powers.

Highway patrol officers recognised Butler and signalled for him to pull over but he allegedly sped off, taking police on a chase until eventually crashing the Navara in a nearby oval.

Police apprehended Powers and Ryan near the abandoned car but had to chase after Butler. He was eventually caught by a police dog.

Butler and Russell are facing charges of murder, while Ryan and Powers have been charged with being accessories after the fact to murder.

Green, who handed herself into police on Sunday and did not apply for bail when she faced court on Monday, is charged with attempted armed robbery with a dangerous weapon.

In a bail application in court on Monday, Powers' lawyer, Matthew Ward, said his client's offer of help to Butler while he was on the run had been restricted to booking him accommodation and giving him money for petrol.

"She was a 25-year-old blinded by affection, blinded by love for an individual," Mr Ward said in describing Powers' motivation.

He also noted Powers had a limited criminal record, strong community ties, would agree to strict bail conditions akin to house arrest if released and her family would also put up a $10,000 surety.

Magistrate Mark Douglass refused to release Powers, saying he was troubled by the allegations against her.

"She's taken deliberate steps to protect [Butler] and make [his] arrest more difficult," he said.

"She has placed her loyalty clearly with the accused persons and not with the Illawarra community.

"That allegation erodes in this court's view the chance of her complying with any bail conditions."

All co-accused will reappear in court on July 17.