A small group of young Perth men have become immersed in an extreme form of Islam that has had civilians around the world joining the Islamic State in Iraq and Syria.
Investigations by _The Weekend West _have found about a dozen youths who have been meeting, donning the black flag and posing with the index-finger salute associated with the terrorist group IS and making contact with extremists in the Eastern States and overseas.
They come from a range of ethnic backgrounds, including some "Aussie reverts" who claim Islam saved them from drugs and crime.
This week, leaders in the Muslim community conceded they were "playing catch-up" with social media and struggling to deter a handful of youths from becoming radicalised.
Four Imams told _The Weekend West _ that self-styled preacher Mohammed Junaid Thorne, a 25-year-old who was deported from Saudi Arabia after his brother Shayden was imprisoned for terrorism offences there, was not welcome in Perth mosques.
WA Islamic Council member Imam Hisham Obeid said leaders had started to "look at ways to make sure this doesn't continue".
"What Mr Thorne is spreading, we don't want," he said. "We want to be part of the Australian society and live in peace and harmony here. We are concerned as well: we don't want his kind of ideology spread in the city."
The mother of a 17-year-old boy from Perth's southern suburbs, who became a follower of Thorne, said her son changed and his behaviour became "radical".
"I don't know when he got involved with Junaid but we have told him we don't want you to associate in any way, shape or form with Junaid and the others," she said.
"My son was with the wrong crowd and I told him to stop. It is hard to tell him it is not right - we try to educate him about the radical behaviour. We told him, 'you don't get involved with something radical, our faith is not like that'."
The father of 18-year-old Zac Obeid, who is close to the Thorne brothers, said he had told his son he did not approve of posing with IS flags because it could damage the Muslim community.
But Gaz Obeid said he was "100 per cent sure" that the group were like "puppy dogs behind a fence" who would never do anything violent or unlawful.
In an interview via Facebook yesterday, Thorne said he could not control what others did but he could "say with confidence that they are not radicalised".
He said he had never been asked to leave a mosque in Perth and that "the Muslim community sort their issues with each other, we don't get the media involved".
He declined to answer some questions, such as whether he supported Australians fighting overseas for IS or would do so himself. In June, a handful of Perth men, including the Thorne brothers, met up in Brisbane with other radicals from the Eastern States.
They posed with IS flags behind a ginger-bearded former hip-hop rapper, a former Curtin University student who said he converted to Islam in the midst of drug addiction in Perth in 2006.
Calling himself "Terry Wrist" (supposedly a play on the word terrorist), he gave an interview that promoted Thorne's lectures, expressing disgust for non-Muslim Australians and encouraging others to leave the "delusion" of this world to join him in paradise.
The interview with "Terry Wrist", believed to be Perth man Matthew Smith who moved to Melbourne several years ago, and his fellow "Aussie revert" friend "Faruq Khattab II", who is believed to live in Perth, has had more than 1500 views since it was posted on YouTube on June 26.
Curtin University terrorism expert Anne Aly, who has had personal experience with some of the young men on campus, said it was difficult to know who might take up arms to fight for their "brothers" and who may be just fuelled by bravado.
"The one-finger sign and black flags are showing a level of support for IS," she said. "It could be a token or it could become part of their identity - that they become the one-fingered warrior.
"We're only talking about a handful of people but it only takes one to do something."
Dr Aly said the prospect of Australian military involvement in Iraq could increase the threat of terrorism attacks on home soil.
"One scenario could be if young Australians who do not have the means or opportunity to fight the ground battle in Iraq and Syria, they might turn their attention to carrying out homegrown attacks to aid the cause," she said.
"I don't believe that this is a huge threat, but it is a threat, nonetheless, and we need to be proactive in tackling the IS narrative now. There is a real urgency for the government and Muslim leaders to counter the narrative of IS that is justifying and calling for homeland attacks."
Thorne has spoken at the Al Risalah Islamic centre in Sydney under the banner of Milatu-Ibrahim, whose media person Abu Bakr walked off the set of the SBS Insight program this week after warning the Government was bringing harm to its citizens if it had troops in Iraq or Afghanistan.