Australian anti-Islamic State (IS) fighter Ashley Dyball has been detained in Germany and risks being charged.

The 23-year-old Queensland man has been fighting against IS forces with a Kurdish militia called the YPG in northern Syria, but was apparently travelling through Europe during a break from the battlefield.

Mr Dyball’s Australian lawyer, Jessie Smith of Melbourne firm Stary Norton Halphen, confirmed that Mr Dyball was detained by German authorities, but said it was unclear whether he would be charged or returned to northern Iraq, where his flight probably originated.

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“[I] would personally like to thank the German government for classifying me as a security threat and deporting me back to Iraq my apologies for trying to make the world a better place,” Mr Dyball posted on Facebook earlier on Thursday morning.

Like other Australians who have fought – or attempted to fight – against IS by joining armed groups in the region, Mr Dyball’s legal situation is precarious.

Australian foreign fighter laws mean it is a crime to join armed groups fighting to overthrow the recognised government of a country.

However, it is still unclear whether this would scoop up Australians fighting against IS.

Mr Dyball’s lawyers are also representing Melbourne man Jamie Williams, who was charged under the foreign fighter laws after being stopped at Melbourne Airport on his way to the Middle East to join the YPG.

Mr Williams’ lawyers are arguing that the YPG and its allied groups are the de facto government of a portion of northern Syria, and as such Mr Williams has committed no offence.

Mr Dyball left Queensland earlier this year, telling his family he was taking a holiday, but travelled to Syria to fight against IS.

His friend Reece Harding and another Australian, Ashley Johnston, have been killed fighting with the YPG.