Kosovo President Hashim Thaci has been accused of war crimes by a special international prosecutor in The Hague.
Mr Thaci and others "are criminally responsible for nearly 100 murders", torture and enforced disappearances, the prosecutor said.
The accusations - covering Kosovo's independence war against Serbia - are being assessed by a judge at the Kosovo Specialist Chambers who will decide if the case goes to trial.
Mr Thaci has denied any wrongdoing.
In its announcement, the Special Prosecutor's Office (SPO) said that, on 24 April, it had filed a 10-count indictment with the KSC "for the Court's consideration". It has not released details about the alleged war crimes.
"The Indictment is only an accusation. It is the result of a lengthy investigation and reflects the SPO's determination that it can prove all of the charges beyond a reasonable doubt," it said.
The statement also said Mr Thaci and another of the accused, Kosovo politician Kadri Veseli, have sought to "obstruct and undermine" the SPO's work "in an attempt to ensure that they do not face justice".
A pre-trial judge now has six months to decide if the court will issue charges.
Allegations of organ-trafficking against the Kosovo Liberation Army (KLA) - the rebel movement that Mr Thaci led - were first set out by a former Hague war crimes prosecutor, Carla del Ponte in 2008. The EU-backed court was set up to investigate the claims.
Kosovo's government has angrily denied the allegations, calling them "baseless and defamatory" ahead of the publication of a report in 2010.
Mr Thaci has been in power in Kosovo since the end of the war - most recently as president of Kosovo.
The independence war in 1998-1999 cost more than 10,000 lives and only ended after a Nato air campaign.
Kosovo declared its independence in 2008, something Serbia still does not recognise.
Mr Thaci was due to travel to Washington DC for planned talks with Serbia's leadership in the White House on Saturday.
He has now cancelled the trip.
The Kosovo Specialist Chambers (KSC) has suddenly broken its silence in the most dramatic manner. It has not just revealed that Kosovo's president is the subject of an indictment for war crimes and crimes against humanity, but also accused him of "repeated efforts… to obstruct and undermine the work" of the court.
For anyone who has ever attempted to get information from the KSC, this is a staggering development. The court has revealed virtually nothing about its work since it was established in 2016. Even when Kosovo's former Prime Minister, Ramush Haradinaj, said that he had been questioned as a suspect last year, there was no confirmation from the KSC.
The fact that the prosecutor has indicted Hashim Thaci is actually less surprising than the manner of the court's announcement. The KSC was set up to examine the allegations in a 2011 Council of Europe report which named Mr Thaci as the leader of a criminal offshoot of the Kosovo Liberation Army involved in drug, gun and human organ trafficking.
At the time, Mr Thaci said the Council report contained "baseless allegations" and threatened to sue the author, Swiss senator Dick Marty.