A 48-year-old Queensland man has been arrested by the state's Joint Counter Terrorism Team (JCTT) over allegations he encouraged acts of violence against political institutions.
Alexander Kent Wadsworth was charged after officers searched a property in Bowenville, outside Toowoomba.
Investigators with the JCTT said Mr Wadsworth allegedly uploaded a number of "concerning posts" to an encrypted social media site.
The JCTT includes the Queensland Police Service, Australian Federal Police and the Australian Security Intelligence Organisation.
In a joint statement, the agencies said the investigation began earlier this month.
"Investigators will allege the man was responsible for the posts, which encouraged others to carry out acts of politically motivated violence in Australia and overseas," they said.
He has been charged with one count of using a carriage service to menace, harass or cause offence.
The offence carries a maximum penalty of five years' imprisonment.
Mr Wadsworth's case was adjourned this morning, and will return to Warwick Magistrates Court next month.
AFP Detective Superintendent Bill Freeman said the AFP was acting on information that people were promoting or encouraging violence online.
"Protecting the community from harm is our highest priority, and that means acting early when we see warning signs of extremist or violent behaviour," he said.
Police Superintendent Jason Hindmarsh said each of the agencies were "focusing on the disruption of violent ideologies".