Several former high-ranking political figures in Kosovo should face charges of crimes against humanity, according to a senior EU war crimes prosecutor.

Clint Williamson, an American prosecutor who has spent three years investigating allegations of ethnic cleansing in Kosovo during and after the 1998-1999 war for independence, said Tuesday that the team he led had found enough compelling evidence to file an indictment against several former leaders of the Kosovo Liberation Army.

There was evidence of war crimes including sexual violence, abductions and other abuses of ethnic Serbs and other minorities by the Kosovo Liberation Army, Williamson told a press conference in Brussels.

The Kosovo conflict, in which ethnic Albanians opposed the government in Belgrade and ethnic Serbs, led to a NATO-backed intervention in February 1998 to force former Federal Republic of Yugoslavia president Slobodan Milosevic’s troops out of Kosovo.

The Kosovo Liberation Army, of which the commanders rose to leadership positions after the war, was the main force leading the Kosovar insurgency against Milosevic.

The investigative team found strong evidence that certain leaders of the rebel army perpetrated violence in order to gain political power and personal wealth for themselves, Williamson said, refusing to comment on whether these leaders were still active in Kosovar politics.

The team, which is called Special Investigative Task Force, was set-up in 2011 to conduct an investigation into the allegations contained in a Council of Europe report by Senator Dick Marty.

Marty’s report claimed that organs were taken out of people killed by the Kosovo Liberation Army during the conflict. It also alleged drug smuggling and assassinations by the army’s leadership.

Williamson stated that his team could file an indictment against these individuals once an appropriate judicial process was established to host a fully independent, impartial and transparent trial.

In 2008, Kosovo declared its independence, which Serbia has vowed never to recognize.