Matthew Gardiner, the former Labor party official suspected of joining the fight against Islamic State, was detained upon his return to Darwin but has been released without charge.

The Australian federal police (AFP) confirmed having spoken to Gardiner but said an investigation was ongoing.

Gardiner, a 43-year old former Australian army combat engineer, was stood down as Northern Territory Labor president when he reportedly left for the Middle East earlier this year.

“The AFP can confirm that it spoke to a Darwin man [on Sunday] following his return to Australia,” an AFP spokesman said in a statement.

“Enquiries relating to his activities while overseas are ongoing and as such it is not appropriate to comment further at this time.”

The AFP had previously confirmed it was investigating the activities of Gardiner, a 43-year-old former Australian army combat engineer and medic who reportedly went to help Kurdish fighters against Isis in northern Syria.

Despite the Australian government having armed Kurds against Isis, any Australian citizen who joins the combat risks being prosecuted under the Crimes (Foreign Incursion and Recruitment) Act of 1978.



Brisbane solicitor Nick Dore, one of the few lawyers with experience of acting in such cases, said they inevitably involved “long and complex” trials.

Dore said if Gardiner was charged, his prosecution could be further complicated if it emerged he had acted solely as a medic, as the legislation defined “hostile activity” in terms of actual violence and presenting “a positive physical threat”.

“That’s a prickly one. That could have serious ramifications to Amnesty and all sorts of things,” he said.

Dore said if Gardiner was charged, the AFP would be required to establish a case against him through his own “words and actions”, including through social media.



Failing that, the AFP would face the more difficult task of gathering direct evidence of his activities in the Middle East, he said.

“The prosecution from here would have to show that Gardiner entered with intent to engage in a hostile act, to go to war – or engaged in a hostile activity,” he said.

“The way to do that would be to find Facebook posts or evidence that clearly indicates what his intention was.

“But if the police can’t find that, they will need to try to find evidence to show that when he got to a certain country, he engaged in an act.”

Gardiner was detained in Darwin on Sunday morning after reportedly returning from the Middle East via Sweden and Singapore, according to the ABC.

He is believed to have sent texts to his wife Andrea just over a month ago to reassure her he was alive, News Limited reported on Sunday.



That followed the death of another Australian, Ashley Kent, 28, in combat against Isis with Kurds in northern Syria.

A spokesperson for the attorney general, George Brandis, told the ABC it was “illegal to fight in Syria for either side of the conflict”.

“If you fight illegally in overseas conflicts, you face up to life in prison upon your return to Australia,” the spokesperson said.

“We know there are some Australians who think they’ve made the right choice in becoming involved in overseas conflicts, but that choice only adds to the suffering in Syria and Iraq and it’s putting those Australians and others in mortal danger.”

Dore said criminal cases involving the foreign incursions act were rare, numbering perhaps half a dozen since 1978.

His client Gerard Michael Little, who trained to join fighters in West Papua, was the first person convicted of attempting to actively participate in a conflict.

“A large percentage of that intention [to join combat] element for Mr Little was from posts on Facebook,” Dore said.

Dore said while the laws were clearly designed to “stop mercenaries”, previous cases involved arms dealers and funders of foreign wars.