The US government has announced the designation of what it calls the Kinahan organised crime group (KOCG) as a “significant transnational criminal organisation” and has imposed sanctions on seven of its key members and three associated businesses.

The designation comes around three years after An Garda Síochána began working with the PSNI, the UK’s National Crime Agency (NCA), the US Drug Enforcement Administration and Department of Treasury and Spanish police agencies to collate intelligence and evidence on the activities of the gang, which is believed to have trafficked tonnes of drugs and firearms around the world for decades.

The US government has offered a $5 million reward for any information leading to the financial disruption of the gang’s Irish leaders Christopher Vincent Kinahan Senior, Daniel Joseph Kinahan and Christopher Vincent Kinahan Junior.

Brian E. Nelson, the US under-secretary for terrorism and financial intelligence, said: “The Kinahan organised crime group smuggles deadly narcotics, including cocaine, to Europe, and is a threat to the entire licit economy through its role in international money laundering.

“Criminal groups like the KOCG prey on the most vulnerable in society and bring drug-related crime and violence, including murder, to the countries in which they operate.

“Treasury is proud to have coordinated so closely with our international counterparts, and the US government will continue to use every available resource to dismantle these criminal networks.”