Garda immigration officers were present during the arrest operation in London and in Kent.
The operation was conducted by British Immigration Enforcement Criminal and Financial Investigation (CFI), assisted by the Garda National Immigration Bureau (GNIB) and the PSNI.
The seven suspects are all nationals of Georgia. They were charged on Tuesday with conspiracy to facilitate illegal immigration.
Georgians whom the gang were smuggling into Britain claimed asylum on landing in Ireland, having been refused entry to Britain.
Georgian nationals are required to have a travel visa if they are travelling through Ireland to another country.
It is understood that more than 300 Georgian nationals have been refused leave to land since 2017, but the vast majority subsequently claimed asylum.
The British gang then organised smuggling some of them into Britain, using forged documentation.
In a statement, the British Home Office said the operation was aimed at “dismantling a suspected organised crime group, believed to be involved in the facilitation of Georgian nationals into the UK, through Ireland”.
It said the investigation began in June, 2017, led by Immigration Enforcement (CFI) and supported by the joint agency task force, which also comprises GNIB, the PSNI, and other law-enforcement agencies.
“The task force enables cross-border co-operation across a range of policing areas, as well as intelligence sharing, which helps keep communities safe and secure,” the statement said.
Immigration Enforcement CFI deputy director Dave McGrath said: “Our investigation is targeting an organised network suspected of being involved in a systematic attempt to help individuals evade the UK’s immigration controls.
“We have been working closely with the PSNI, in Northern Ireland, and the GNIB, in the Republic of Ireland, and that vital co-operation will continue, as the investigation proceeds, with the evidence we have seized today.”
Detective chief superintendent David Dowling, of GNIB, said: “This is an example of the continued co-operation between the relevant agencies in our efforts to target all types of criminal activity, including illegal immigration in both jurisdictions.”
In addition to the six men and one woman charged, two further arrests were made for identity-document offences in Britain.
In a separate operation in Ireland, GNIB officers conducted a search operation last month in Dublin, targeting another Georgian gang involved in smuggling compatriots into Ireland with forged documentation.
One man was arrested and a file is being sent to the DPP in relation to that matter.