Returned NSW woman Mariam Raad has been charged with entering and remaining in parts of Syria that were under the control of Islamic State terror group.
Police say newly obtained evidence prompted the arrest of the 31-year-old in the NSW town of Young on Thursday, as Australian Federal Police and NSW Police investigators searched properties in Young and Parklea.
Raad is expected to face a regional NSW court on Thursday afternoon on a charge of entering or remaining in declared areas, in breach of federal law.
If convicted, she could face up to 10 years in jail.
Police allege Ms Raad, who was recently living in Young, travelled to Syria in early 2014 to join her husband who left Australia in 2013 and joined IS.
It will also be alleged she was aware of her husband's activities with the terror group and willingly travelled to the conflict region.
Ms Raad's husband Muhammad Zahab, a former Sydney maths teacher who rose through the ranks of the terror outfit, is believed to have died in Syria in 2018.
The woman later moved to Al Roj Internally Displaced Persons camp in northern Syria under Kurdish control before returning to Australia in October 2022 as part of the Australian government's controversial repatriation plan.
She was reportedly insistent to the ABC in 2018 that she knew nothing about her husband's work.
"We're, like, now emotionless. I would say probably I was angry [at him]," she told the public broadcaster from a Syrian camp.
She was charged after an investigation by the Joint Counter Terrorism Team (JCTT) that began when she was in Syria and continued following her return to Australia.
NSW Police's counter-terrorism commander said the community's safety was of utmost priority.
"We have zero tolerance for Australians - or anyone - who seek to commit acts of violence or extremism and those considering doing the wrong thing will come under our notice," Assistant Commissioner Mark Walton said.
The federal police commander tasked with monitoring "enduring" terror risks said the JCTT would continue to investigate Australians returning from declared conflict areas
"Individuals will be brought before the courts when evidence supports allegations that returned individuals have committed offences in conflict areas," Acting Assistant Commissioner Sandra Booth said.
"The JCTT will continue to target criminal activity and does not target specific ideologies or beliefs".
The NSW JCTT comprises members of the AFP, NSW Police, the Australian Security Intelligence Organisation and the NSW Crime Commission.
Police said there was no current or impending threat to the Australian community related to Raad.