Fatmir Limaj was a senior figure in the Kosovo Liberation Army (KLA), which fought to throw off rule by Slobodan Milosevic’s Serbia. The war culminated in NATO air strikes in 1999 against Serbia to halt the killing and expulsion of Kosovo’s ethnic Albanian majority.

Limaj and nine other Kosovo Albanian ex-fighters are charged with murder, torture and human rights violations. All pleaded not-guilty on Friday.

The case is the most high profile yet to be tried in Kosovo, which declared independence from Serbia in 2008 with the backing of the major Western powers but continues to be overseen by NATO and the European Union.

Observers say the case highlights the culture of intimidation that has long hampered the justice system in the impoverished country of 1.7 million people, where clan loyalties are paramount and KLA veterans are revered as heroes.

Much of the prosecution case, compiled by an EU prosecutor, rests on the testimony of former KLA prison guard Agim Zogaj, or Witness X before he was found dead in Germany in September, hanging from a tree in a park.

German authorities say Zogaj killed himself. His family are less certain, and say he faced constant threat. Zogaj had only agreed to testify in June 2009 after gunmen attacked his home in Kosovo and he was wounded.

An EU mission overseeing policing and justice in Kosovo, known as EULEX, sent him to Germany as a protected witness.

Political analyst Krenar Gashi said it was a surprise a witness had even come forward against Limaj, who, he said, “has widespread and powerful political support.”

“Generally, there’s absolute denial that former KLA members could have committed war crimes,” Gashi told Reuters.

“The pressure on this witness (Witness X) was intense ... as his testimony was more or less testimony against a cause perceived as fundamental to this society.”

The indictment accuses Limaj of ordering Witness X, Zogaj, to kill two captured Serb police officers, held during the war in a makeshift prison in the village of Klecka in central Kosovo.

According to the indictment, Zogaj admitted killing the two men, and kept a diary detailing life in the prison, including names of prisoners, dates of capture, releases and executions.

Limaj is also accused of torturing a Serb military officer in Klecka. The officer’s remains were found in a grave with four other bodies.

Limaj, who went by the nom de guerre of Celik (Steel), was acquitted in 2005 of similar charges at the United Nations war crimes tribunal for the former Yugoslavia in The Hague.

He was greeted as a hero on his return to Kosovo and entered Kosovo’s previous government as transport minister and was a senior official of Prime Minister Thaci’s Democratic Party of Kosovo.

He has been under house arrest since September and also faces an investigation into alleged corruption. The war crimes trial is presided over by a panel of two foreign judges and one local.