Manuela Mareso told the Summer School of Investigative Reporting in the Serbian town of Novi Sad: “In recent months, there have been police investigations showing that these groups are doing business with the Italian mafia.”
Drug trafficking from Montenegro to Italy has been going on for the past years, according to the police, she said.
But Mareso added the Balkan criminal groups are now smuggling weapons and drugs along the same channels they use for moving contraband cigarettes.
She said: “According to the police, Serbian-Montenegrin criminal gangs are the most powerful in Europe.
Italian police uncovered five cells of the Montenegrin mafia network in Udine, Milan, Florence, Perugia and Bari earlier this year.
Italian police have previously charged Milo Djukanovic, the current, suspected of heading an organized criminal group of smuggling tons of cigarettes, drugs and weapons.
The trial was dropped after Montenegro became independent in 2006 and he received immunity as a head of government.
The Italian government has recently invested €5 billion in energy and infrastructure projects.