The European police agency Europol said on Friday the eastward expansion of the European Union will prove a boon to flourishing organised crime groups, with border controls relaxing as the EU grows from 15 to 25 countries next May.
Europol's annual report on organised crime says Mafia-style groups will use new member states as bases for trafficking drugs and people.
"The (EU) area is widening and we will get a common area of crime just as we have a common area of economy, tourism and social life," said Europol Director Juergen Storbeck at the report's presentation in Rome.
"(Enlargement) is profitable for us, for our legal activities, but it is also profitable for criminals."
The report said powerful crime networks were getting increasingly sophisticated, moving away from the traditional, hierarchical model seen in Mafia movies and towards a cell-based structure that made it harder for police to find the top bosses.
It said there were signs international crime groups were moving their activities to the EU newcomers, which were also becoming focal points for money laundering.
The 10 countries joining the bloc next year are the Czech Republic, Poland, Lithuania, Latvia, Estonia, Hungary, Slovakia, Slovenia, Cyprus and Malta.