More than 800 people have been arrested in Europe, North America and Australia as part of a massive law enforcement operation targeting gangsters who communicated using the AN0M device.
AN0M allowed criminals to talk to each other on encrypted devices but it turns out the FBI had designed the device themselves and were listening in from the get-go.
FBI Assistant Director Calvin Shivers told reporters at Europol's HQ in The Netherlands: "They actually came to us seeking these devices…The results are staggering.”
He said FBI agents and local law enforcement officers were able to read the messages of underworld figures in 100 countries as they smuggled drugs, discussed arms deals and even mulled over contract killings.
On top of the arrests police in numerous jurisdictions seized eight tons of cocaine, 250 guns and £34 million in cash and cryptocurrencies as well as several luxury cars.
Australia’s Prime Minister Scott Morrison said it had "struck a heavy blow against organised crime.”
Europol dubbed the investigation Operation Trojan Shield and said more than 100 murders had been prevented and several large-scale drug shipments thwarted.
The full details of the undercover operation may never be known but it appears the criminal syndicates ended up using an encrypted device - AN0M - which the FBI themselves had designed.
It enabled law enforcement to monitor their communications for 18 months.
According to unsealed court documents cited by US media outlet Vice, the FBI managed to distribute the AN0M devices through the Phantom Secure network.
Australian police said among those who bought the ANOM device were Chinese and Vietnamese gangs, Latin American drug cartels and motorcycle gangs such as the notorious Comancheros.
AN0M follows on from the successful disruption of two major encrypted phone networks, Encrochat and SkyGlobal, which were both used by organised crime.
A spokesperson for Britain's National Crime Agency said: "The National Crime Agency is proud to have been a partner in what has been an innovative and complex operation to target criminals operating globally and using encrypted communications platforms."