* Operation Ironside is the name of the Australian Federal Police arm of a global covert investigation, involving the US Federal Bureau of Investigation and Europol.

* It began almost three years ago.

* It targeted an encrypted communications platform used by organised crime gangs around the world.

* The platform was an app called ANoM, installed on stripped-back black market mobile phones that could only send messages to another device.

* Criminals needed to know a criminal to get one.

* The devices grew in popularity among criminals after high-profile figures - dubbed "criminal influencers" - vouched for them.

* But ANoM was being covertly run by the FBI, allowing law enforcement to piggyback chatter between gangs.

* The encrypted communications included plots to kill, mass drug trafficking and gun distribution.

* In Australia, the alleged perpetrators include the Italian mafia, outlaw motorcycle gangs, Asian crime syndicates and Albanian organised crime figures.

* More arrests are expected domestically and offshore under a coordinated global response connected to Operation Ironside.

WHAT HAS THE OPERATION TURNED UP IN AUSTRALIA SO FAR?

* Some 224 Australians have been arrested and more than 100 charged in every mainland Australian state.

* Seizure of 3.7 tonnes of drugs, 104 weapons, about $45 million in cash and assets expected to run into the millions of dollars since 2018.

* The AFP has also acted on 21 direct threats to kill, potentially saving the lives of a significant number of bystanders.

INVOLVEMENT OF OTHER LAW ENFORCEMENT AGENCIES

* The European Union police agency, Europol, and the FBI will hold their own press conferences on Tuesday and into Wednesday Australian time.

Australian Associated Press