Two WA Police officers who were chasing a car minutes before it crashed at high speed into a tree, killing three people, have given emotional testimony to an inquest about what happened on the night.

Key points: The driver of the car was jailed for 12-and-a-half years over the high-speed crash

The driver of the car was jailed for 12-and-a-half years over the high-speed crash The police pursuit lasted for 35 seconds and officers did not breach any guidelines

The police pursuit lasted for 35 seconds and officers did not breach any guidelines The constable who was driving the police car wants more pursuit training for officers

The officers were in a marked police car that briefly pursued the speeding vehicle in the southern Perth suburb of Cockburn in December 2015, before the driver lost control and smashed into a tree.

The car split in two, killing rear seat passengers, Amy-Lee Armstrong and her partner Kyrone Eades, both 23.

A third passenger, Ashley De Agrela, died later in hospital.

The driver of the vehicle, Matthew Conduit, who was under the influence of methylamphetamine and alcohol, received only minor injuries in the crash.

He was sentenced in August 2017 to 12-and-a-half years in jail after pleading guilty to a string of charges, including dangerous driving occasioning death.

Police aborted chase before coming across crash

An inquest into the case is mandatory because police were involved in the incident, and on Wednesday the officer driving the police car, Senior Constable Joel Vanson, was the first witness.

He broke down as he recounted arriving at the scene of the crash moments after it happened and hearing people in the wreckage screaming, at one point saying to coroner Barry King, "I'm sorry, it was terrible".

Kyrone Eades (right), pictured with mother Francina Wynne, was among those killed in the crash. ( Facebook: Francina Wynne )

Constable Vanson said he had earlier decided to try to intercept the car because it was going in excess of the speed limit and had gone through a red traffic light.

He said he activated his lights and sirens while his partner was on the police radio detailing what was happening, but the other car seemed to be more powerful and was travelling faster than theirs.

He told the inquest they were continually doing risk assessments of the situation, but decided to abort the pursuit when the car turned off its headlights and went onto the wrong side of the road.

Moments later, after driving around a bend, he and his partner came across the crash scene.

Constable Vanson said no findings were made against him after an internal investigation into the crash.

The investigation revealed the pursuit lasted for only 35 seconds and concluded the officers had not breached any police guidelines.

Call for more pursuit training

Constable Vanson, a trained pursuit driver, told Mr King he would like to see officers receive more practical follow-up training after their initial test.

Senior Constable Joel Vanson says officers should be given more follow-up pursuit training. ( ABC News: Jon Sambell )

He said trained drivers had to do an annual online refresher test every two years, but he would like to see a "physical component to it."

He said he had "reluctantly" been involved in further police pursuits since the crash.

Constable Vanson again became emotional when he was asked to describe the effect the fatal pursuit had had on him, saying while dealing with death came with the role of being a police officer, it was different when officers were directly involved.

"It puts a different spin on things and it's not something you can explain. To understand it you have to experience it," he said.

'A wall of woodchips and dirt'

Constable Vanson's partner, Darren Cramer, also struggled to contain his emotions as he recounted seeing the victims in the wreckage.

Senior Constable Cramer said while he had been to plenty of fatal police incidents during his career, he will remember that night "for the rest of his days".

Police officer Darren Cramer also struggled to contain his emotions as he gave evidence. ( ABC News: Jon Sambell )

The court was told the car was travelling at estimated speeds of around 130 kilometres an hour before the crash, with another motorist, Marcus Downs, testifying he heard the sound of the car travelling through the air just before impact.

He said it sounded like "white noise" and was followed by what he called "a wall of woodchips and dirt".

"Out of the wall of woodchips came half the car. I braced myself for impact because I was almost positive it was going to hit me," he told the court.

Mr Downs said he managed to steer his car off the road, but the debris from the wreckage popped two of his tyres.

Kyrone Eades' mother, Francina Wynne, and other members of his family were in the Coroner's Court for the inquest, which they described as heartbreaking.

Speaking outside court, they said it was important for them to be there to find out the truth.

Coroner King said he expected to hand down his findings in a few months and expressed his condolences to the families of the victims.