SYDNEY — An Australian man killed in the Syrian conflict was a former soldier who went absent without leave several years ago, a senior official revealed Wednesday.

Reports said that Caner Temel, 22, was killed on the front line in January after traveling to Syria to fight in the civil war, joining up with the Islamic State of Iraq and the Levant (ISIL) radical jihadist group.

“From his name and from the photograph that the media showed, that matched the name and a photograph we had of a young soldier who served three years ago,” Assistant Defense Minister Stuart Robert told the Australian Broadcasting Corporation.

“He only served for 17 months. He went absent without leave in September 2010. And of course if you go absent without leave, after 28 days if we can’t find you, we’ll discharge you.”

Robert said Temel would have done basic training, including construction work, arms training and a limited amount of explosives work.

He said Temel’s reasons for leaving the Australian military were unclear, nor was it known when he went to Syria or whether he was a dual passport holder.

But Robert said the case highlighted concerns the government has about the prospect of Australians traveling to Syria to fight in the three-year conflict, which has left more than 130,000 dead.

“I think it’s a concern to all Australians that we have Australian citizens choosing to go and fight with foreign militaries,” Robert said. “It’s deeply concerning.

“If reports are correct — and some commentators are speaking of up to 100 Australian citizens who’ve chosen to join the fight in Syria — that is a concern because it’s clearly a criminal act if you go and serve with a foreign military.”

“At present the [defense] department has no knowledge of any other serving military personnel from Australia who are over in Syria fighting,” he added.

In January, Australia’s government expressed concern at the growing numbers of its citizens travelling to Syria to fight alongside rebel groups, with several reported deaths.

Attorney General George Brandis said he was worried about Australians returning radicalized and with new skills to commit extremist acts.

ISIL fighters have fought Syria’s regime but have been increasingly battling a coalition of moderate and Islamist rebels angered by their abuses of rival fighters and civilians.