A crash that left a woman dead after her car was hit head-on by a four-wheel drive driven on the wrong side of the road in Western Australia’s South West is being investigated by the Major Crime Squad.

Jenni Pratt, 61, was killed in the crash on Bussell Highway near Capel on Saturday afternoon, while the driver of the 4WD survived and is in a critical condition in hospital.

Jenni Pratt died at the scene of the head-on collision. Photo: Facebook

Mobile phone and dashboard-mounted camera footage appears to show the 4WD’s driver deliberately crossing to the wrong side of the road into the path of oncoming vehicles before the crash.

Oncoming motorists are seen slowing down or driving off the road to avoid a head-on collision.

The footage then shows the green 4WD colliding head-on with a white SUV on Bussell Highway before rolling and bursting into flames.

Ms Pratt died at the scene.

Her 54-year-old passenger remains in hospital in Bunbury with serious injuries.

The man allegedly behind the wheel of the 4WD has been identified as Shaun Southern, a 45-year-old divorced father-of-two who had lived alone at a caravan park in Bunbury.

Mr Southern remains in a critical but stable condition at Royal Perth Hospital after being thrown from the vehicle in the crash.

Witnesses have reported he had earlier hurriedly taken off in the 4WD from Wonnerup Beach in Busselton with a camping tarp hanging off the back of the vehicle.

Shaun Southern has been identified as the alleged driver of the 4WD. Photo: Facebook

He was reported to have left all of his camping gear, fishing rods, phone and wallet at the site.

Detectives from the Major Crime Squad have taken over the investigation into the crash.

They want to speak to anyone who witnessed the crash or saw Mr Southern’s 4WD on Wonneruup Beach, Layman Road or Bussell Highway, from Busselton to the Capel Drive intersection, prior to the crash.

They also want to speak to anyone who spoke to Mr Southern last Friday or Saturday.

-ABC, with AAP