Months after a Council of Europe report accused Kosovo's top leaders of trafficking in human organs, the EU rule-of-law mission (EULEX) said a preliminary probe was still trying to establish whether enough evidence exists to begin a formal investigation.

The mission says it can only launch an official investigation if enough hard evidence is received, and no specific persons are as yet under the spotlight.

EULEX said that anyone who had evidence to support the grave accusations made in the report, including Marty, needed first to to come forward and submit their findings to EULEX prosecutors.

"We have exchanged letters with Mr Marty. We have not yet received any hard evidence from him," a EULEX spokesperson told Balkan Insight.

"At this stage we have nothing more to add. When we have more to say, we will say it," the spokesperson added.

The report caused a bombshell when it was released in December, as it linked former Kosovo Liberation Army, KLA, fighters, including the current Prime Minister, Hashim Thaci, to organised crime and accused them of harvesting the organs of Serbian prisoners and others in Albania.

But Marty has refused to provide any evidence for his claims to the EU mission in Kosovo, saying the mission was not up to handling the investigation and thus an "ad hoc" judicial structure needed to be set up, which would operate outside Kosovo.

EULEX disputes this. "We have full confidence in our own witness protection unit, which has already shown itself capable of handling high-level and sensitive cases," EULEX said.

Serbia, meanwhile, has sent a proposal to the UN asking the international body to launch an independent investigation into the allegations.