A delusional obsession with a woman he could never have has allegedly sent a French backpacker on a frenzied stabbing spree, killing one and critically injuring another.
Smail Ayad, 29, had fawned over Mia Ayliffe-Chung, 21, for several days, telling other backpackers at the Home Hill hostel the pair were deeply in love and married.
The Bulletin understands his obsession with Ms Ayliffe-Chung turned deadly on Tuesday night, after hearing the British backpacker had posed for revealing photos in a magazine and did not reciprocate his feelings.
Furious at the unrequited love, he allegedly stabbed Ms Ayliffe-Chung multiple times while screaming "Allahu Akbar", leaving her to die on the floor of her Shelley's Backpackers room.
It is understood another British backpacker and friend Thomas Jackson, 30, came to Ms Ayliffe-Chung's aid and was stabbed multiple times in the face, chest and stomach, suffering horrific injuries.
Up to 30 backpackers witnessed the frenzied attack and tried desperately to intervene, although the Bulletin understands Ayad, a kickboxing champion who has trained in Thailand, allegedly made threats against them and stabbed a hostel employee in the leg.
Late last night senior police praised the efforts of the backpackers, employees and police who ran to the aid of Ms Ayliffe-Chung and Mr Jackson, saying their actions were "incredibly brave under the circumstances."
Yesterday afternoon as police transferred Ayad from hospital to the watchhouse, he allegedly bashed two police officers, after they had to pull over on Woolcock St as he was lashing out in the back of the police paddy wagon. Both officers were hospitalised.
Police were forced to use capsicum spray on Ayad to subdue him and the Bulletin understands it took seven officers to get Ayad into a padded cell, as he continued to scream "Allahu Akbar".
It will be alleged this was the second time Ayad lashed out at police, with body-worn cameras showing the gruesome scene that confronted the first responders and a blood covered Ayad mumbling "Allahu Akbar."
When police tried to arrest him at the backpackers' hostel, Ayad was wrestled to the ground and handcuffed, although the Bulletin has been told he continued to kick police, forcing them to handcuff his legs to his hands.
District Superintendent Ray Rohweder said police were confronted with a horrific scene, but acted "tremendously".
"As we understand it at the moment, the French gentleman, the person who is helping us, has attacked the two British nationals," Supt Rohweder said.
"Witnesses have said they observed the person attacking one of the persons and as a result of that there was another altercation and subsequently the male person has gone upstairs at the accommodation complex.
"Police have arrived and I can tell you the scene that confronted police was terrible ... there was a lot of blood, there were two persons, one was deceased and one was certainly in a very bad way."
The Australian Federal Police and the Joint Counter Terrorism Unit were in Home Hill yesterday and are investigating any links between Ayad and radical organisations, although they have not found any evidence of radicalisation.
AFP Commander Sharon Cowden said they would be working with their overseas counterparts to determine if there was a terror element to the attack.
"We are considering all options here. We are working very closely with our partner agencies to ensure that if there is any indication that this has an extremist slant to it or this person had been radicalised, we would be able to discover that.
"At this stage, we have no evidence of that."
Ayad had not been charged last night.