Very little human remains were found among the carnage of a horror road crash that killed four children and two adults in the Northern Territory.
A 4WD carrying six people was on fire for more than five hours after colliding with a road train near a small town in the Katherine region on Friday afternoon.
NT Police Commissioner Michael Murphy said investigations were ongoing, although alcohol could have been a factor.
"This is a very distressing scene, we've never seen anything quite like it," he said on Monday.
Detective Senior Sergeant Brendan Lindner says it will be a long process to identify the victims.
"The intensity of the fire meant that there was little human remains left," he said.
Forensic teams are using DNA analysis to identify the victims and are not expected to complete their work until Thursday.
The driver of the road train and a passenger believed to be sleeping were taken to hospital with burns and broken bones but have since been released.
The road train was carrying mangoes and used cars and had just refuelled with 10,000 litres of petrol in Darwin when the 4WD swerved into its lane.
The truckie and his passenger managed to extricate themselves and tried to help the passengers of the car before both vehicles ignited into a fireball.
The collision is the deadliest territory road crash in more than 15 years and police say the psychological impact will be "phenomenal".
"There's nothing to suggest the truck driver has done anything wrong, in fact, his actions at this stage sound commendable," Sgt Lindner said.
Police have received dashcam footage from people in the area at the time which is helping them determine the cause of the crash.
They believe the family was from the NT's Big Rivers region and the 4WD had been bought the previous week.
Police reopened the Stuart Highway on Sunday after significant delays in the area over the weekend.
There have been 19 lives lost on NT roads this year.
