The accused creator of a secret app used by networks of organised criminals has been arrested after encrypted phones were allegedly used to plot murders and drug trafficking.

Dozens of people have been taken into custody following days of raids targeting users of the Ghost app.

The bulk of the arrests were in NSW, but alleged criminals in Victoria, Western Australia, South Australia and the ACT were also caught in the net.

Some 700 Australian Federal Police members were involved in the operation, which also involved an international task force targeting offshore links.

Thirty-eight people were arrested across the nation, with more people expected to be charged on Wednesday.

The police operation also prevented 50 deaths or serious injuries through infiltration of the communications networks, AFP officials said.

The raids, which stemmed from a tip-off from French authorities in 2021, also took down a global encrypted communications network, investigators said.

A 32-year-old man, who police allege created and maintained the network, was arrested at a home in Sydney’s south and is due to face court on Wednesday.

He has been charged with numerous offences, including supporting a criminal organisation and dealing with the suspected proceeds of crime.

He allegedly distributed modified smartphones for about $2350, which paid for a six-month subscription to the encrypted network and tech support.

The man lived with his parents and did not have a criminal history, police said.

There were about 376 of the handsets active around the nation when he was arrested on Tuesday, the AFP said.

Authorities modified software updates sent to the devices, allowing investigators to monitor communications.

Encrypted communication networks, including some reliant on dedicated devices, have become a focus for law enforcement targeting transnational organised crime.

The AFP and the FBI previously ran a purportedly secure communications platform, ANOM, which criminals used to discuss murder plots, drug and weapons deals in the belief that their messages were secret.

It was exposed as being part of a law enforcement operation in 2021.

AFP deputy commissioner Ian McCartney said the latest operation established the agency as a world leader in cracking communication networks.

“Taking down dedicated encrypted communication devices takes significant skill,” he said.

“But the holy grail is always penetrating criminal platforms.”

This post was originally published on Michael West.