The widow and son of former Serbian President Slobodan Milosevic are facing charges of running a cigarette smuggling ring during the 1990s.
Mirjana Markovic and her son have been in exile in Russia since 2003
Mirjana Markovic and Marko Milosevic are suspected of making millions of dollars from the scheme, a Serbian special prosecutor has said.
Slobodan Radovanovic said Serbia would issue an international arrest warrant for the pair and freeze their assets.
Ms Markovic and Mr Milosevic have been living in exile in Russia since 2003.
Fearing arrest on embezzlement charges, the two were absent from Slobodan Milosevic's funeral in Serbia in March 2006.
The former president died of a heart attack in his prison cell in The Hague while being tried on charges of war crimes and genocide.
The charges related to atrocities carried out in Kosovo in 1999, to crimes against humanity committed in Croatia in 1991 and 1992, and to alleged genocide in Bosnia-Hercegovina between 1992 and 1995.
Mr Radovanovic said the Milosevic family had taken advantage of the international sanctions imposed on Serbia during that period to organise a profitable business illegally importing cigarettes.
The criminal gang they ran made tens of millions of euros, he said.
The special prosecutor for organised crime said Ms Markovic and her son then transferred the illicit funds into dozens of offshore accounts.
"The prosecution will request all their property in Serbia to be frozen, as well as their accounts abroad," Mr Radovanovic told the Beta news agency.
Mr Radovanovic said his evidence had been handed to Belgrade district court's department for organised crime and that he expected an investigative judge to request an international arrest warrant soon.
Fifteen other people were arrested this month on similar charges.