Canberra: The Australian Federal Police (AFP) is investigating 51 Italian organized crime clans across the country, including 14 from the infamous 'Ndrangheta, taking their orders from bosses in Calabria in southern Italy.

Police believe up to 5,000 mafia members are operating in Australia, with AFP assistant commissioner Nigel Ryan telling a news conference on Tuesday "their overall membership could potentially be similar to that of patched members in Australian outlaw motorcycle gangs".

A secret messaging app used by police to infiltrate criminal gangs has revealed thousands of Italian mafia members are operating in Australia.

The crime network is responsible for trafficking 70% of the world's cocaine, according to the AFP. In Australia, that extends to cannabis and methamphetamine.

"The 'Ndrangheta is flooding Australia with illicit drugs and are pulling the strings of Australian outlaw motorcycle gangs (OMCG), who are behind some of the most significant violence in our communities," said Mr. Ryan.

"They have become so powerful in Australia that they almost own some OMCGs, who will move drugs around for their 'Ndrangheta financiers, or carry out acts of violence on behalf of the 'Ndrangheta."

He said the AFP will target the Italian organized crime and money-laundering syndicates washing billions of dollars a year through the Australian economy.

The AFP has managed to compile a family tree of the mafia from data obtained from Operation Ironside.

It was a three-year undercover sting in which authorities infiltrated the phones of organized crime figures through an encrypted mobile app, called ANOM.

Criminals were convinced to use the messaging service through word of mouth in the underworld, believing it was secure and off the police radar. Little did they know that the 25 million messages sent on the platform were being closely monitored by the AFP and FBI.

Since authorities revealed the truth about AN0M a year ago, 383 alleged Australian criminals have been charged with more than 2,340 offenses.