NSW Police have reportedly linked the Sydney teenager behind a fatal shooting at the Parramatta Police Headquarters with a British radical associated with Islamic State.
The Australian reports Farhad Jabar Khalil Mohammad was communicating with the extremist online and the connection between the pair is central to the police investigation into the 15-year-old's final movements.
The development comes as police investigate the possibility Farhad Jabar did not act as a 'lone wolf' killer and had, in fact, been working on orders from other radicals.
"The possibility the teenager was used by extremists is a strong line of enquiry," a senior officer told The Daily Telegraph.
"That includes searching his computers, electronic devices and who he was in contact with on the days leading up to the shooting and the day itself."
The young gunman who callously murdered a Sydney police worker has been linked to an Islamist group already under investigation for radicalising children as young as six.
7 News understands Farhad Jabar was at a mosque attending a lecture given by Hizb ut-Tahrir just before donning a black robe and launching a shocking daylight attack in a Parramatta street.
A police investigation into Hizb ut-Tahrir was launched in 2014 after 7 News unearthed video of a six-year-old boy at one of the group’s youth meetings being told "you're never too young to be a Soldier for Khalifa".
Police have appealed for calm amid fear of revenge attacks as shock at last Friday’s terrorist murder at Parramatta gives way to hate.
A Facebook tribute page has labelled the teenage gunman a hero and threatened to kill infidels.
Meanwhile far right wing groups are demanding an end to Islamic immigration.
Police have been called over simmering tensions in suburban Parramatta as a senior Islamic leader was caught swearing and kicking at the media on a city street.
Social media is now alive with hate messages from both sides.
One page has been set up calling the killer a hero.
“… death to the evil police state of Australia who killed this young child … all he is guilty of is being muslim !!” it read.
Meanwhile, the Australia First party letterbox dropped Parramatta with messages saying “Islam has no place in Australia.”
One Nation leader Pauline Hanson has called for tighter Muslim immigration laws in the wake of the "politically motivated" Sydney shooting last week.
Ms Hanson and Derryn Hinch weighed in on the tragic incident on Sunrise Monday, with the controversial politician's views, in which she referenced the Quran, causing conjecture.
"Both sides of parliament are not doing enough to address this whole issue," Ms Hanson said from Queensland.
"What Islam stands for it is not compatible with our country ... let the Muslim countries take them.
"There are 400 on our streets now under surveillance," she went on. "This is is the only religion we've had so many problems with. It's a political ideology that's not compatible with our way of life.
"We need to know what's being taught in Islamic schools and mosques ... get out of your glasshouses and go and see what's happening."
It has sparked calls for calm from people including Prime Minister Malcolm Turnbull.
“We have to work with the Muslim community very collaboratively,” he said.
"In terms of these so-called lone wolves, it is too early to comment or really for me to say at any rate to what extent this individual who murdered Mr Cheng was self-motivated, self-activated."
"There is a lot of work being done to investigate this murder," said the leader, who on the weekend said the attack "appears to have been an act of terrorism".
Turnbull said the government must adapt to changing threats and "constantly calibrate our response and learn from what we're doing".
"The need to counter radicalisation is there, the government's commitment to countering it is absolutely undiminished," he said.
Robyn Torok, an expert in online radicalisation from Edith Cowan University, told the national broadcaster ABC that Islamic State militants are recruiting young Westerners to launch attacks in their home countries.
"They're giving them information... on how to hide their extremist identity, how to fly under the radar, how to deal with certain agencies, how to buy certain weapons and how to hid their true intent," she said.
Muslim community leader Dr Jamal Rifi said Muslims were not a threat.
“We are part of the solution,” he said.
Police have urged the public to resist the efforts of “some among us who will try to use what happened on Friday to divide us”.
Those comments came as Jabar’s family made its first public comment on Facebook.
“RIP little bro,” the message read.
At the murder scene overnight controversial former terror suspect Zaky Mallah added his condemnation.
“ISIS, you have no religion. You have no god,” he said.
He is pushing for volunteer “mosque monitors” to patrol prayer rooms and report suspected extremists.
“Send them out to every single mosque in Australia and start monitoring our places of worship. This needs to be done ASAP,” Mallah said.