The Queensland teenager suspected of joining an Al Qaeda-linked terror group in Syria did not make strong bonds with the local Muslim community and may have been radicalised over the internet, an Islamic leader says.

Only six months ago Oliver Bridgeman, 18, denounced extremism on Facebook however it is now believed he left his hometown of Toowoomba in March to join the Al Nusra Front, the official Syrian affiliate of Al Qaeda, and several Islamist factions.

His parents insist he has not taken up arms after leaving the country under the guise of doing aid work in Indonesia.

The mosque Oliver went to in Toowoomba has distanced itself from the controversy.

He occasionally went to prayer sessions at the Garden City Mosque after his family moved from the Gold Coast last year.

Before they relocated his mother had approached Toowoomba Islamic community leader Professor Shahjahan Khan to help with a smooth transition.

"She wanted to get help from the community," he said.

"I think the parents were quite supportive (of his conversion to Islam)."

Oliver, who had set up a Facebook page in 2014 under the alias Yusuf Oli, occasionally mixed with Muslims his age but did not appear to form any lasting attachments.

"I don't think there was an attachment to anybody, a good relationship with anybody," Professor Khan said.

"He was just by himself mostly."

Professor Khan did not believe Oliver became radicalised within the community.

"We were really shocked to hear this news, it was totally surprising to us," he said.

"Whatever he is doing is not related to Toowoomba, it is something else, that come from the internet or somewhere else."

Oliver playing football in the rain at Ubud in Bali, posted on March 27. ( Facebook )

Told parents he was doing aid work in Asia

Oliver was school captain of Coombabah State High school on the Gold Coast last year but completed year 12 at Toowoomba's Harristown State High School.

Oliver at the Nyepi parade in Bali, posted on March 20. ( Facebook )

Toowoomba's detective Inspector David Isherwood said the teen told his parents he had gone to Indonesia to do aid work but when they went to pick him up from his return flight he was not at the airport.

"His parents hit the panic button," Detective Isherwood said.

They filed a missing person report and the Federal Police and overseas security agencies discovered he had left Indonesia to Turkey.

His parents, who have not been named, have said in a statement they do not believe he was supporting terrorists.

"We had no indication that he was making plans to travel to the Middle East, however we now know that he is probably there," his parents said in the statement.

"We do not believe he is participating in fighting of any kind, nor do we believe he is supporting or participating in terrorist acts."

In December 2014 he denounced radicalism on his Yusuf Oli Facebook page.

"Extremism is as a result of lying against Allah, for when the extremist fails to produce evidence and interpretation, he resorts to lying against Allah to fulfil his whims: "Do not commit excess in your religion or say about Allah except the truth."

Oliver Bridgeman told his parents he was leaving Australia to do aid work in Indonesia. ( Facebook )

Difficult to escape the clutches of terrorists

Dr Anne Aly, a researcher in counter terrorism at Curtin University, expects to hear more instances of radicalisation.

Sorry, this video has expired Young people increasingly showing no signs of radicalisation, Dr Anne Aly says.

"More and more we are seeing young people being radicalised in the isolation of their rooms, looking at the internet," she said.

"It may not be the attraction of the ideology itself, it may actually be the attraction of the violence, it may actually be the attraction of the lifestyle, or even the attraction of wanting to do something, of being an activist in some form."

Dr Aly said as long as the Daesh or the Islamic State had a huge presence on the internet they would keep targeting young people with their propaganda.

"As long as they are able to portray themselves as being an attractive option for young people and as long as there are young people who see that as an attractive option, we will certainly be seeing more of it," she said.

"Anybody who goes over there, if they live through it, it's very, very difficult to get out once you're there.

"It's very, very difficult to escape the clutches."