Joint criminal investigations between the Garda and its counterparts in other EU member-states was authorised yesterday by the Minister for Justice, Mr McDowell.
The Criminal Justice (Joint Investigation Teams) Act, 2004, was brought into effect yesterday.
It provides for the setting up of joint investigation teams by mutual consent of member-states for a specific purpose and limited period of time.
The teams will carry out criminal investigations with a cross-border dimension in one or more of the EU states setting up the team.
Such teams have been used in the past for cross-border crime, especially organised crime.
However, they have generally been set up on the basis of "understandings" rather than an internationally agreed framework for establishing and operating them.
The Department of Justice said that, when investigating offences with a cross-border dimension, experience had shown they could benefit enormously from the support of law enforcement and other relevant personnel from another state with which there were links to the offences in question.
In the past, one obstacle has been the lack of a specific agreed structure within which such support could be availed of.
The EU Council framework decision on joint investigation teams provides agreed conditions for such a structure.
Mr McDowell said: "This Act is a further example of the EU taking measures to facilitate more effective co-operation in combating crime, particularly serious crime such as terrorism, drug-trafficking, fraud and organised crime generally."