Public response has helped police to map the journey an accused killer took from Christchurch to the West Coast where he allegedly attacked two hitch-hikers.

Detective Senior Sergeant Darryl Sweeney said he had received many reports of possible sightings of the vehicle being driven by the 38-year-old accused of killing Amy Farrall.

"We're now aware the vehicle travelled on the Lewis Pass to Greymouth,'' Mr Sweeney said.

He said he believed the blue Nissan Terrano was travelling State Highway Seven, Lewis Pass Road mid-to-late afternoon on Saturday.


Mr Sweeney praised the public for providing information and hoped more people would come forward with possible sightings of the vehicle.

He said police had gathered a lot of evidence from Ms Farrall's car and home, and the investigation was progressing well.

He expected the scene examinations to be completed tomorrow afternoon.

The 38-year-old from Otaki has been charged with the sexual violation and murder of Ms Farrall, a 24-year-old community support worker. Her body was found in the boot of her car at a city supermarket on Sunday.

Police say the man, who had recently been staying at Ms Farrall's Woolston home after moving to Christchurch, killed her, dumped her body and fled to the West Coast via Greymouth, where he picked up two hitchhikers and attacked them.

Tourists Niki Honda, 27, and Michaela Brandl, 28, are both in a stable condition in Christchurch Hospital.

Ms Honda is recovering from pelvic injuries, and Ms Brandl was stabbed three times in the carotid artery on the side of her neck, and struggled to open the locked doors of the attacker's vehicle.

It's believed that the driver then tried to run over Ms Honda who had escaped from the moving vehicle.

"They're both very lucky. Things could've been a lot worse,'' a source told APNZ.

"One of the women used a small travel knife, with just a small blade, to try and fight the guy off. She was pretty desperate.''

Ms Honda, 27, is said to be recovering well in hospital but needs rest, an official from the Japanese Embassy said in Christchurch yesterday.

The accused man was granted name suppression at a special court sitting at his hospital bedside on Wednesday, and was remanded to the High Court in Christchurch later this month. He has undergone surgery for dog bite injuries sustained during his arrest after a five-hour stand-off with police.

- additional reporting by Kurt Bayer & Patrice Dougan