The grim theory casts a gloomy light on the chances of bringing to a close the savage roadside killing that inspired the film Wolf Creek.

The ruthless drug runner spent 20 years in jail for shooting British backpacker Peter Falconio and tying up Mr Falconio's girlfriend Joanne Lees before she made a harrowing escape.

Police have announced a new reward to find Peter Falconio body, 24 years on from his outback murder.

Bradley John Murdoch is currently serving a life sentence for the murder on a remote stretch of the Stuart Highway in Australia

The grim theory casts a gloomy light on the chances of bringing to a close the savage roadside killing that inspired the film Wolf Creek.