Australian Adam Brookman in court on return from Syria
A nurse who says he was forced to work with Islamic State militants in Syria has appeared in court in Sydney.
Adam Brookman, 39, was detained on Friday at Sydney International Airport relating to "his alleged involvement in the conflict in Syria", police said.
He is the first Australian to return from Syria or Iraq since the country brought in new anti-terror laws.
Justice Minister Michael Keenan had said he was entitled to return but would be investigated.
Mr Brookman, a Muslim convert, says he travelled to Syria to do humanitarian work but was forced to work with IS when he was injured in an air strike and taken to a militant-controlled hospital.
"The man voluntarily surrendered himself to Turkish officials in Turkey on Tuesday, 21 July," a police statement said.
His return to Australia had been negotiated with Australian government and international agencies, it said.
The police have not specified the charges against Mr Brookman.
He did not speak as he appeared in the Sydney court via video link.
He will be moved to Melbourne at the request of anti-terrorism officials, local media reports.
New Foreign Fighters legislation has made it a crime to assist militant groups in the Middle East.
Australia is on high alert for attacks by radicalised Muslims, including those returning home from fighting in the Middle East.
In December last year, the country specifically banned travel to Syria's Raqqa province, which is held by IS.
It means anyone entering the area could face up to 10 years in prison unless they have a legitimate reason, including family visits, journalism or aid work.
According to the government, at least 100 Australians are fighting with terror groups in the Middle East, and another 150 people in Australia are known to be supporting such groups.