The National Crime Agency (NCA) has "successfully penetrated" a top-secret communications system used by criminals to trade illegal materials including drugs and guns.
The BBC reports that the NCA teamed up with forces across Europe on the UK's "biggest and most significant" law enforcement operation.
After messages on the EncroChat platform were intercepted and decoded, it contributed to over 800 major crime arrests in Europe.
Watch a full news report on the bust as it happened below:The NCA also reported that in excess of two tonnes of drugs, several dozen guns and £54m ($67.34m) in suspect cash were seized as a result of the communications system being penetrated.
French and Dutch police established the investigation with the help of Europol - the EU agency for law enforcement cooperation - as well as the NCA.
Wil van Gemert, the deputy executive director of Europol, said that the hacking of the network had enabled the "disruption of criminal activities including violent attacks, corruption, attempted murders and large-scale drug transports" at a press conference in the Hague.
A man being arrested as part of the EncroChat bust is pictured below.
The Europe-wide operation took three months to complete has had the biggest known impact on gangs of organized criminals. There have been 746 arrests in the UK alone, which included two law enforcement officers.
The Metropolitan Police Commissioner, Dame Cressida Dick, described the bust as a "game-changer" after her force made 171 arrests and seized £13.3m ($16.58) in cash.
The house pictured below is being searched as part of the bust.
Dame Cressida said: "This is just the beginning. We will be disrupting organized criminal networks as a result of these operations for weeks and months and possibly years to come."
Nikki Holland, NCA director of investigations, said the operational team described the bust as being "akin to cracking the enigma code".
"They see this as that significant in terms of getting that inside information, effectively having a person inside an organized crime group telling us what they're up to," she said.
