France's Gwladys Epangue, who defeated Tina Morgan of Australia, and Sandra Saric of Croatia, who outscored Puerto Rico's Asuncion Ocasio Rodriguez, both collected bronze medals.
Last month they arrested Mr Saric's brother, at Italy's request, as part of a co-ordinated operation involving over 80 arrests in Italy, Montenegro and Slovenia.
Milorad Veljovic, chief of the Serbian police, said that Mr Saric could not be the real boss of the gang, a remark taken to mean that it was a controversial Montenegrin businessman.