A radical Perth preacher has praised militants responsible for beheadings and mass killings in Iraq and labelled Christians and Jews filthy rapists.
In a series of online postings and videos Junaid Thorne, 24, has called on Muslims to defend their religion.
Junaid, who spent much of his youth in Saudi Arabia, sits in front of the black flag of al-Qaida breakaway group ISIS and calls on young Australian Muslims to reject their moderate leaders.
ISIS, also known as ISIL, has been responsible for the murders of unarmed Shi'ite Muslims and has posted grisly pictures of executions online in a bid to attract radicals from around the world.
In an online posting on June 10, Junaid praised ISIS militants and congratulates them on the capture of the city of Mosul and the liberation of militant prisoners.
"May Allah reward them for such a heroic and glorious act," he wrote. "Congratulations (on) this victory and liberation."
ISIS is listed as a terror organisation by the Federal Government, meaning anyone who recruits, trains, directs or provides support or funds for the group faces up to 25 years jail.
The Government has already cancelled passports of some Australians who have gone to join the war in Iraq and Syria.
An Australian Federal Police spokesman said officers were aware of the videos but would not confirm if an investigation had started.
Counterterrorism sources told The Weekend West they had been watching Junaid and his elder brother Shayden since the pair were detained in Saudi Arabia by terrorism investigators last year.
Foreign Minister Julie Bishop today confirmed authorities were aware of the situation.
She said it was a crime to support or promote terrorism and those who did so faced severe penalties including 25 years in jail.
“I can confirm these matters are under investigation,” she said.
Shayden was given 4½ years jail but was pardoned in February.
Junaid was detained and questioned and deported to Australia last year and has since gained a cult following among some young Muslims.
He has held lectures in Perth and the Eastern States.
Edited videos of the lectures show Junaid referring to jailed terrorists as defenders of Islam and telling followers they have a duty to defend their faith.
"Look at the prisons around the world and what do you see? People who stand up for Islam," Junaid says. "What have you done for this religion?
"You knew what was happening in this world, yet you chose to sit at home and do nothing."
He outlines what appear to be rules of engagement for religious war, including circumstances in which it is acceptable to kill innocent women and children as collateral damage.
Junaid, who did not reply to requests for an interview, regards himself as the spiritual leader of a group known as Millatu Ibrahim Perth.
He has previously denied that Millatu Ibrahim is linked to a radical European group with the same name, the same flag, and is banned in Germany.
Curtin University counterterrorism expert Anne Aly said Junaid and Millatu Ibrahim Perth should be viewed with concern by local authorities.
"We should be cautious of them," she said. "They espouse a dangerous view of the world and a misinformed doctrine of Islam that has the potential to divide the community and influence young people in the wrong direction and dangerous directions.
"If they grow in their influence, then we have got a real situation on our hands." Former head of the Australian Federation of Islamic Councils Ameer Ali said Junaid's views were not shared by most WA Muslims.
"They are a pest actually, more of a nuisance and now and then journalists might write about them but it is not a phenomenon we want here," he said. "It would be unfair to tarnish all Muslim youth with this."
WA Police would not comment on Junaid specifically but said it worked closely with the Muslim community and Federal Government agencies to counter the threat of radicals.