European policing agency Europol said on Tuesday that the takedown of Encrochat, an underground company that offered criminals supposedly secure encrypted communications, led to more than 6,500 arrests and US$980 million (about RM4.6 trillion) in seized assets.
The system had an estimated 60,000 users when it shut down abruptly in June 2020, and Europol revealed the following month that law enforcement officials had been intercepting users' communications for months.
In a statement on Tuesday, Europol offered its first overview of the results of the takedown, which it said had "sent shockwaves across organised crime groups in Europe and beyond".
Police have analysed more than 115 million "criminal conversations", Europol said, helping prevent "violent attacks, attempted murders, corruption and large scale drugs transports."
The agency said investigations spawned by the takedown have so far led to the seizure of 100 tonnes of cocaine, 30 million pills of "chemical drugs", nearly a thousand vehicles, hundreds of properties and dozens of boats and planes.
The police statement gave no details on whether the owners of Encrochat themselves had been arrested.
French and Dutch authorities were due to hold a press conference in Lille later on Tuesday.
Partial results of Encrochat-linked investigations have previously been announced by French, Dutch, and British police in 2020 and by German police in 2021.
Encrochat sold modified Android mobile devices for around 1,000 euros each and charged users hefty subscription fees with the promise their communications would remain encrypted and secret.
It shut down abruptly in June 2020 after its unidentified operators apparently realized they had been compromised.
Europol said the company had routed encrypted communications through servers in France.
"Eventually, it was possible to place a technical device to go beyond the encryption technique and obtain access to users’ correspondence," Europol said on Tuesday.