Crime gangs across the north are bracing themselves for a law enforcement crackdown linked to a secret messaging service similar to EncroChat.
Known as Sky ECC, the network was believed to be one of the most secure end-to-end encryption messaging platforms available, until it was smashed by European security agencies last year.
The service is known to have been used widely by criminals across the globe, including in Ireland.
The international use of messaging services by crime gangs emerged when details the National Crime Agency (NCA)-led Operation Venetic were made public in June 2020.
It targeted the EncroChat encrypted messaging service and resulted in dozens of people facing charges in local courts.
The Irish News understands that at the time Operation Venetic was launched the use of EncroChat had been phased out by some criminals with many switching to the more discrete Sky ECC option.
Details about Sky ECC broke last year when Dutch and Belgian officials carried out a series of raids and made multiple arrests.
Security agencies in those countries cracked the encrypted service resulting in a huge number of messages being harvested.
Some reports suggest that investigators intercepted about one billion encrypted messages from Sky ECC.
The NCA has refused to confirm if it is investigating the use of Sky ECC in the north.
However, in a statement the PSNI said the NCA is investigating the network along with other "EU agencies".
It is understood that to date no-one has been arrested in relation to the use of the messaging system.
The sophisticated Sky ECC network, which was operated by Canadian based firm Sky Global, is said to have been used with iPhone 6S mobile phones and later models.
Once installed the service could be accessed by pressing an icon, disguised as a fake Sky TV logo, and entering a 16-digit number which brought the user into their individual profile.
A further 16-digit code was then required for a picture or message to be sent.
It is understood the service did not allow for the use of voice messages.
As a security measure it is understood the network automatically wiped itself of all data at intervals.
It is believed there were 170,000 Sky ECC devices registered worldwide.
Two former senior officials linked to the message company were charged last year in the US with a conspiracy to violate the federal Racketeer Influenced and Corrupt Organizations Act.
Solicitor Ciarán Shiels, of Madden and Finucane Solicitors, who represents clients in the EncroChat case, believes more arrests could follow as a result of the Sky ECC probe.
"It would be a fair assessment of the situation to say that many persons suspected of being active members of multi-jurisdictional organised crime gangs who have so far escaped the swoops from law enforcement....could well find themselves arrested regarding alleged criminal contacts," he said.
In a statement, the NCA said: “The NCA does not routinely confirm or deny the existence of investigations, however we are aware of action taken by international partners against Sky ECC.
"Tackling the criminal use of encrypted communication is a priority for the NCA and its partners in the fight against serious and organised crime.”
A spokeswoman for the PSNI said it is "aware of the ongoing investigation by NCA and EU Agencies.
"The PSNI work with a range of partners, including the NCA and EU Agencies, to tackle organised crime in all its forms."