Marty's report was based on a two-year investigation that included interviews with judicial authorities, politicians, international bodies and U.S. intelligence services.
"In confidential reports spanning more than a decade, agencies dedicated to combating drug smuggling in at least five countries named Hashim Thaci and other members of his Drenica Group as having exerted violent control over the trade in heroin and narcotics," the report said.
It said Thaci's links to organized crime date back to 1998 when his Drenica Group took over the Kosovo Liberation Army and criminal enterprises in the region.
The report names Thaci as one of the key players in the trafficking of organs of Serb prisoners after the 1998-99 conflict.
Guards at the prison-like base in Tirana murdered ethnic Serb prisoners to cut out and sell their kidneys on the black market, the report charges.
Serbian deputy war crimes prosecutor Bruno Vekaric called the report a great victory for Serbia in the fight for truth and justice, Serbia's Tanjug news agency reported.
The report will officially be presented to the Council of Europe Thursday.