European Union ministers have agreed to increase the powers of Europe's police agency, Europol, to give it an operational role in investigations.
It is hoped Europol will be better able to fight terrorism
EU justice and interior ministers, meeting in Vienna, agreed that Europol needed to become more efficient.
But changes cannot be made until all 25 EU states ratify the protocols of Europol's founding convention.
Europol provides intelligence and support to national police forces, but cannot arrest suspects.
Germany, France, Ireland, Italy, Luxembourg, Portugal and Sweden have not yet ratified the protocols, one of which provides for joint investigations.
Crime scene function
Europol, which is based in The Hague, the Netherlands, was founded in 1992 to improve co-operation between the police forces of European Union members.
However, it has been restricted to the role of providing expertise, information and technical support.
The EU's anti-terror co-ordinator, Gijs de Vries, said there was a general desire to now see Europol take on an operational role.
"To strengthen the fight against terrorism we need to give Europol clear competences," he added.
Arresting suspects will remain the domain of national police forces.
"But we want our officials to be able to go to the place of a crime, search or confiscation and to advise national authorities what to look for," said Europol Director Max-Peter Ratzel.
It is hoped that the changes will make Europol better able to tackle cross-border crimes like terrorism, people and drug trafficking, and money laundering.