Canberra, Dec 7 (IANS): A man who fought against the Islamic State (IS) in Syria has arrived back in Australia and was released without charge after police interrogation, the media reported on Monday.

Ashley Dyball, 23, left Brisbane in May to join a Kurdish military campaign against IS in northern Syria, and was arrested in Germany earlier this week while taking a break from the battlefield, ABC reported.

Dyball - also known as Mitchell Scott - arrived in Melbourne on Sunday night, where he was questioned by the Australian Federal Police for several hours.

His lawyer Jessie Smith said he was "interviewed, released without charge pending further enquiry".

Dyball reached Brisbane on Monday morning with his parents, who said they were proud of their son.

Dyball posted on Facebook that after "feeling as wanted as Justin Bieber" he was glad to be home, but was "still currently under investigation".

Australia is on high alert for attacks by radicalised Muslims, including those returning home from fighting in the Middle East.

In June, it was reported that another Australian man, Reece Harding, was killed fighting with the Kurdish YPG militia group against the IS in Syria.