A 20-year-old man has been charged with the theft of a car linked to several high-profile incidents, including the alleged "politically motivated" arson attack on Melbourne's Adass Israel Synagogue in December.
Detectives arrested the man in Williamstown before executing a search warrant at a home in Melton South on Wednesday, where they seized multiple items.
The man was charged with motor vehicle theft, along with failing to provide access to applications on his phone.
Victoria's acting premier Jaclyn Symes suggested it could lead to further arrests.
"A breakthrough such as this and getting to an arrest demonstrates that the investigation is at a critical point," she told reporters on Thursday.
"It's presumed there are others involved and once you have an arrest you have the ability to obtain more information."
No one has been charged with carrying out the firebombing and the accused car thief is the first person to be accused of any offence linked to the attack.
Ms Symes would not be drawn on whether a joint counter-terrorism task force's efforts to uncover who ordered the attack were being stifled by criminals using encrypted messaging apps.
The ability of police to find "small criminals" at the end of the chain instead of the "masterminds" was frustrating, Executive Council of Australian Jewry president Daniel Aghion KC said.
"There is clearly more going on and no doubt the police are doing their best but we are not getting to the people who are planning these attacks and arranging for them to be carried out," he said.
"Until we find those who are ultimately directing these violent crimes, we have no prospect of stopping them or delivering justice for the victims."
Police allege the 20-year-old, granted strict conditional bail ahead of a scheduled court hearing in early October, stole a blue 2020-model VW Golf sedan at Melton on November 29, 2024.
The stolen car was used in other offences, including the Lux nightclub arson at South Yarra in November, as well as an arson and shooting at Bundoora.
It was then used in the synagogue arson attack on December 6, police allege.
Investigators do not consider the Bundoora and South Yarra incidents politically motivated attacks.
Two of the synagogue's three buildings in Ripponlea, in Melbourne's southeast, were gutted.
Inside at the time were two congregants preparing for morning prayers who escaped, with one suffering minor injuries.
Photos and CCTV footage released by counter-terror police in May showed a Golf sedan repeatedly passing the synagogue before parking directly outside its main entrance.
Three people donning hoodies and masks got out of the vehicle and used an axe to damage the entrance of the building.
Investigators have combed through CCTV from more than 1400 locations and believe multiple offenders are directly and indirectly linked to the incident.
Detectives have also been investigating several more recent alleged acts of anti-Semitism across Melbourne, including an incident at the Israeli restaurant Miznon and the alleged arson attack on a East Melbourne Synagogue on July 5.
A group of worshippers fled when a man allegedly set the building on fire during weekly services.
Police later charged Angelo Loras, 34, from Sydney's west with multiple offences including reckless conduct endangering life and criminal damage by fire.
Israeli Prime Minister Benjamin Netanyahu condemned the "reprehensible anti-Semitic attacks" and demanded the federal government "take all action to deal with the rioters to the fullest extent of the law".
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