Tareq Kamleh first appeared in a propaganda video in early 2015. "He went on a camping trip with some people – I don't know who they were or what they told him, but it was after that," a former hospital colleague said. "I didn't think we had too many radical fundamentalists up in Mackay." They said Dr Kamleh stopped drinking alcohol, abstained from sex, grew his beard and withdrew from the friends he had made. "I never really saw him after that, he hung around but never with us. He went from a fun-loving success with the ladies type of bloke, a bit of a playboy, to straight hard-line fundamentalist saying no, he would never have sex again unless he was married," the colleague said.

Tareq Kamleh, the Australian doctor who featured in an Islamic State propaganda video over the weekend. Credit:Facebook They pressed their friend on the "complete" personality change and Dr Kamleh spoke of his parents, who had always given him the choice as to what extent he wanted to practise his religion. They said he said he spoke of his German mother who had converted to Islam to marry his father. Australian doctor Tareq Kamleh. Credit:Facebook "She was the quite strict one in adhering to it. She was the one who was always orthodox and very strict," they said.

The colleagues said he spoke of breaking up with his girlfriend, who he cheated on constantly, if she did not also convert. They said they recognised him immediately when the IS propaganda video was made public. "He got some of the best training from hospitals he went to and then to declare jihad on the West ... it's very disappointing," they said. "He was a really good doctor, he was really good at what he did and he was really well-trained. Patients really liked him, everyone really liked him." A former associate of Dr Kamleh backed up the colleagues' description of the doctor's family.

The associate told Fairfax Media that Dr Kamleh's father grew up in Palestine but lived a largely secular life after moving to Australia. However, his mother was a German Catholic who converted to Islam and became "ultra-religious", the associate said. They said the mother's strict religious views influenced the rest of the family. Dr Kamleh is believed to have grown up in Perth, where his parents still live, and has a sister who is a nurse in Adelaide. The doctor, believed to be in his late 20s, appeared in an Islamic State propaganda video the group posted on Friday.

In it, Dr Kamleh, who refers to himself as Abu Yusuf, urges other Muslim medical professionals to travel to IS-controlled territory and join in the Islamic State Health Service. "I saw this as part of my jihad for Islam, to help the Muslims' ummah (community) in the area that I could, which is the medical field," Dr Kamleh says in the video. "I wished that I'd come a lot sooner." Dr Kamleh is believed to have graduated from the University of Adelaide and started as a pediatric registrar at the Adelaide Women's and Children's Hospital in February 2011, where he worked until the end of his contract in January 2013. He also spent one term at Alice Springs Hospital as a pediatric junior registrar , from February to May 2012, and later moved to the Mackay Base Hospital in Queensland in 2013.

Dr Kamleh's medical registration is valid until September this year, and lists the Perth suburb of Subiaco as his primary place of practice. - with Rania Spooner