Garda negotiation specialists have helped secure the safe return of eight Irish citizens, who had been held against their will in foreign countries in the past three years.
The role played by highly trained members of the Garda national negotiation unit, which is part of the force's Special Tactics and Operations Command (STOC), has not previously been revealed.
One other Irish citizen, James Hillis, who disappeared in Colombia in 2019, is still on the missing list.
Mr Hillis, who is from Wexford, is feared to have fallen foul of a drug trafficking gang,
Over the last few years, members of the negotiation unit (NNU) have assisted the local authorities in securing the safe return of Irish citizens in Nigeria, Ghana, Sudan, South Africa, Cambodia, Brazil, Algeria and Romania.
Gardai have been deployed on the ground dealing with incidents in Ghana, Nigeria, Sudan and Cambodia and worked closely there with officials from the Department of Foreign Affairs and local authorities.
Some of those who disappeared were victims of kidnapping by local crime gangs, seeking a ransom, while others were held for other reasons.
While efforts were under way abroad to ensure the Irish were set free unharmed, the gardaí kept in regular contact at home with their families, updating them on the progress made in their inquiries. The incident in Ghana was described as particularly complex and as well as the gardaí it also involved police from Luxembourg, Belgium and Germany.
Apart from the Hillis case, the longest negotiation to secure a release was in Sudan and lasted three months.
Most of the incidents have involved crime gangs but gardaí say they are often concerned that the kidnappers could sell or pass on their victims to more organised terrorist groups, creating fresh difficulties and much bigger ransom demands.
But there have been no terror-related kidnaps of Irish citizens since the abduction and murder in Iraq in 2005 of Irish-born Margaret Hassan, who grew up in London
She carried an Irish passport and the government in Dublin, under Taoiseach Bertie Ahern, repeatedly emphasised her Irish connections in an attempt to "soften" the stance of the kidnappers.
Some to start a fresh life, particularly after the last recession.
Gardaí are reluctant to discuss details of the individual cases where the NNU has been deployed, at home or overseas.
The head of the NNU, Detective Inspector Tony Ryan explained that their operations were deliberately kept low key as any publicity, particularly in the overseas incidents, could be counter productive and put the victim on greater danger.