Police have ruled out any form of radicalisation in the fatal stabbing of a 21-year-old British backpacker in north Queensland.

Key points: Man who came to Ms Ayliffe-Chung's aid was also attacked

Man who came to Ms Ayliffe-Chung's aid was also attacked Police hope to interview suspect Smail Ayad today

Police hope to interview suspect Smail Ayad today Police investigating if Mr Ayad had a romantic interest in Ms Ayliffe-Chung

Mia Ayliffe-Chung was just days into a three-month stint working on a farm as part of her visa extension in Australia when she was killed at Shelley's Backpackers in Home Hill, 100 kilometres south of Townsville, on Tuesday night.

A 30-year-old British man who came to her aid is clinging to life in hospital after also being attacked.

Police said the suspect, 29-year-old Frenchman Smail Ayad, who was staying at the hostel, used the Arabic phrase "Allahu akbar" during both his arrest and the attacks, which were witnessed by up to 30 people.

Flowers and messages of support have been left outside Shelley's Backpackers. ( ABC News: Nancy Notzon )

Superintendent Ray Rohweder said police were starting to get a picture of the exact circumstances surrounding the tragedy at Home Hill.

"What I can say, at this stage, [is] there is absolutely no — and I repeat — there is absolutely no indication of any form of radicalisation or any particular motive in relation to this matter," he said.

"But we're certainly far from reaching any positive conclusions as to motive or anything like that.

"We intend to attempt to interview the suspect today and I would imagine that we will be in a position to either charge or release the suspect."

He said Mr Ayad underwent a psychiatric assessment and may have used cannabis prior to the attack.

'No indication' of romantic interest

Superintendent Rohweder said police were investigating whether the suspect had a romantic interest in Ms Ayliffe-Chung.

"There is certainly at this stage no indication — from Mia's point of view — that there was any sort of romantic connection," he said.

"We are certainly looking at everything that's occurred down there over the last couple of days.

"I don't believe there was any romance ... there is no doubt about that — again, certainly not from Mia's point of view. But that is certainly a line of inquiry."

Suspect 'bit arresting officer'

He said the suspect was violent with police officers.

"When we transported the suspect from the Townsville hospital to the Townsville police station, the suspect behaved in an extremely violent manner, which necessitated police stopping the motor vehicle and attempting to restrain him," he said.

"As a result of that, police received some injuries, including just cuts and abrasions but also a bite to the leg, and other police then arrived and assisted the two detectives, and he was subsequently placed in a van and taken to Townsville police station."

Forensic police continue to examine the scene at the Home Hill hostel. ( ABC News: Nancy Notzon )

Superintendent Rohweder said there was a large amount of evidence at the scene to be gathered by forensic investigators.

"There are a lot of technologies that we employ to ensure that we glean from a crime scene every piece of evidence that we can and that takes a lot of time," he said.

"We also have people coming in from Brisbane today to do some further testing."

He said police were also still speaking to witnesses.

"There's a large body of witnesses and these people are [fruit] picking so they're out at farms and doing that sort of thing," he said.

"We need to interview each and every one of those witnesses so they can tell their story as it occurred.

"I've viewed the CCTV of what actually occurred - there's no-one that can view that CCTV that doesn't come away feeling sick to the stomach. It's just absolutely horrific."