Three men are expected to be charged with engaging in a terrorist act over an alleged arson attack on a Melbourne mosque.
Victorian police said they arrested a Meadow Heights man, 29, in relation to the 2016 incident following a vehicle stop in Roxburgh Park late Saturday night.
Police said they would allege that the 29-year-old and two other men, already in custody awaiting trial on terror related charges, "caused a serious fire at the Imam Ali Islamic Centre on 11 December 2016".
The three men would be charged with engaging in a Terrorist Act, police said.
The two men in custody, a 25-year-old and a 27-year-old, would also be charged with engaging in a terrorist act over a fire at the Imam Ali Islamic Centre in November 2016, police added.
Australian Federal Police Assistant Commissioner Ian McCartney said the arson attacks were "designed to intimidate and influence those that attend this mosque and the wider Islamic community".
"These actions have no place in our society," McCartney said on Sunday.
"Individuals or groups who think they are above the law when it comes to this type of intimidation should think again."
Victoria Police Assistant Commissioner Ross Guenther said the pending charges represented the high quality of effort delivered by the tri-agency set up in Melbourne.
"Victoria Police is proud to serve a diverse multi-faith and multicultural community, and will not tolerate this kind of behaviour in our community," he said.
All three men are expected to be charged on Sunday.