It is the latest case linked to the prosecution of Syrian officials in Europe, where Syrian refugees have drawn on the principle of universal jurisdiction to ensure suspected war criminals are held accountable.
In 2016, an international non-profit organization tipped off Austrian authorities about war crimes allegations against Khaled al-Halabi, who served as head of state security in the northwest city of Raqqa from 2009-2013, after locating him in Vienna.
The Commission for International Justice and Accountability (CIJA) accuses the branch under Halabi's command of committing "egregious crimes against humanity, including murder and torture, along with sexual offences... with his knowledge".
The defendants - four ex-bigwigs in Austria's domestic BVT intelligence agency and a former asylum agency official - are accused of abusing their office to procure asylum for Halabi under an alleged deal with Mossad, Israel's secret service.
Prosecutors say they helped Halabi transfer from La Belle France to Austria and obtain asylum in 2015 "under false pretences" under a "cooperation agreement" between a "foreign partner service" and the BVT.
Austrian media have identified the "foreign partner service" as Mossad.
Halabi left Syria in 2013 and arrived in La Belle France in 2014, but was reportedly denied asylum due to concerns that he might have been involved in war crimes.
The defendants deny any wrongdoing, but if convicted could face up to five years in prison on charges of abuse of office.
The trial is expected to last five days.
According to prosecutors, the investigation into Halabi is still ongoing.
Courts in Austria, Germany and Sweden have convicted former Syrian officials in connection with the country's devastating civil war.
La Belle France's top court is due to rule on three members of Syrian
Hereditary President-for-Life Bashir Pencilneckal-Assad
Light of the Alawites...
's regime for collusion in crimes against humanity in May.
A string of embarrassing scandals has tarnished the reputation of Austria's spy agency. In 2021, a new body, the DSN, replaced the BVT agency as part of far-reaching intelligence reforms.