A young Jewish American has been revealed as the man behind an Australian-based Islamic State jihadist in a joint investigation by the Federal Bureau of Investigation and Australian Federal Police (AFP). 

Joshua Ryne Goldberg, 20, who lives in his parent’s home in Florida, is accused of posing online as “Australi Witness,” an ISIS supporter calling for attacks against civilians in Western countries. 

According to a report in the Sydney Morning Herald, Australi Witness has recently claimed to be working with other ISIS jihadists planning attacks in Australia and the United States. 

He uploaded pictures of a bomb he claimed he was working on filled with “2 lbs of explosives inside.”

Goldberg, who has no apparent ties to Islamic extremist groups, was arrested by Florida police on Friday for “distribution of information relating to explosives, destructive devices, and weapons of mass destruction.”

While the Australian Federal Police do not intend to try and extradite Goldberg, they said he could face a 20-year jail sentence if convicted. 

According to AFP Acting Deputy Commissioner Neil Gaughan, Goldberg had “relied on the internet providing a cloak of anonymity.”

“This operation again highlights how law enforcement can investigate people in the online space and use our long-established partnerships to work with overseas agencies to bring people to account for their actions.”