Counter-terrorism police have arrested a 65-year-old man in Melbourne following an investigation into alleged links to the Islamic State terrorist organisation, commonly known as ISIS. The man was arrested during a police operation at a property in Carlton on Wednesday morning, 23 September 2026.

According to police, investigators allege the man pledged allegiance to ISIS and acted as an online propagandist for the organisation. Police allege he distributed approximately 10,000 files containing violent extremist material and ISIS propaganda.

The arrest was carried out by Australia's counter-terrorism authorities following a lengthy investigation. Officers conducted a raid at a home in Carlton as part of the operation. Further information about the evidence gathered during the investigation is expected to be provided by the Australian Federal Police.

Police have not established the allegations through a court finding at this stage. The man has been arrested and is expected to face legal proceedings, meaning the allegations remain matters for the court to determine.

The investigation focuses on the alleged use of online platforms to distribute extremist material. Counter-terrorism authorities monitor the online dissemination of terrorist propaganda because such material can be used to promote extremist organisations, encourage support for terrorism or provide information associated with violent attacks.

The large number of files allegedly distributed by the man is a significant part of the police case. Investigators will examine the nature of the material, how it was distributed, who may have received it and whether other offences were committed.

The arrest took place in Carlton, an inner-city suburb of Melbourne. Police have not indicated that there is an immediate threat to the wider public connected with the arrest. The investigation remains active, and authorities are expected to provide additional information as the legal process develops.

Counter-terrorism investigations often involve cooperation between federal and state law-enforcement agencies. In this case, the Victorian Joint Counter Terrorism Team has been involved in the investigation. The team brings together agencies responsible for investigating terrorism-related offences and national-security threats.

The arrest comes as Australian authorities continue monitoring extremist activity both online and offline. Police agencies have increasingly focused on the role of digital communications in extremist networks, including the distribution of propaganda and instructional material.

Authorities have not released all details of the allegations while the investigation is continuing. Any future court proceedings will provide an opportunity for the evidence and allegations to be tested through the judicial process.

The Australian Federal Police is expected to address the media about the arrest and provide further information about the investigation. Updates may include the specific charges being considered, details about the alleged online activity and information about the police operation.

For now, the 65-year-old remains an accused person and has not been convicted of any offence. The investigation and subsequent court proceedings will determine the legal outcome.