Thaci "does not want to influence the (independent) investigation opened by US prosecutor John Clint Williamson," Kosovo deputy prime minister Hajredin Kuci told local media.
Prosecutor Williamson heads up a working group set up by the European Union's EULEX rule of law mission in Kosovo to investigate the claims made in Marty's report.
In the report, Marty said that members of Thaci's Kosovo Liberation Army (KLA) guerilla forces set up prison camps for Serbs and Kosovo Albanians accused of collaborating with Serbs on Albanian soil during and right after the 1998-99 conflict.
In some cases it is alleged that prisoners were killed and their organs harvested to be sold on the international black market. Marty, from the liberal FPD, writes that the group within the KLA carrying out the alleged crimes was closely linked to Thaci.
The Kosovo prime minister has always denied the charged and earlier threatened Marty with legal action.