Kosovo Serb Budimir Maslar shows photo of his sister missing during 1998-1999 Kosovo war, in front of "Wall of crying", a wall covered with photos of missing Serbs. Maslar is among the Serbs who fear a loved one may have been killed for a kidney. (AP/Srdjan Ilic)

RRIPE, Albania Europes top human rights watchdog is launching a probe into a bone-chilling allegation: That ethnic Albanian guerrillas may have kidnapped Serb civilians at the end of Kosovos 1998-99 war, removed their organs and sold the body parts on the black market.

A United Nations inquiry into the issue in 2004 proved inconclusive. So did a recent investigation by The Associated Press, which obtained U.N. and Serbian documents detailing what was uncovered at a farmhouse in remote north-central Albania: bloodstains, syringes, empty bottles of muscle relaxant, surgical gear and other material. The family living in the house in Rripe offers a plausible explanation for everything the investigators found.

The allegations were first made public in a memoir last year by Carla Del Ponte, the former chief U.N. war crimes prosecutor. In Madame Prosecutor, an account of her tenure as head of the International Criminal Tribunal for former Yugoslavia, Del Ponte said her office was tipped to possible organ trafficking.

Although the information was tantalizing, Del Ponte wrote, in the end, the attorneys and investigators on the KLA cases decided that there was insufficient evidence to proceed. They left it to U.N. officials and the local Kosovo and Albanian authorities to investigate further, which never happened.

Now, a probe is being led by Dick Marty, the Swiss senator who headed an investigation into claims the CIA operated secret prisons in Eastern Europe. Marty, working on behalf of the Council of Europe, would not comment before his Balkans fact-finding mission is completed.

Serbian authorities claim to have uncovered new evidence. They say two wealthy Europeans a Swiss and a German apparently were among the recipients of kidneys, livers and other organs harvested in Albania and sold via middlemen in a macabre but meticulously orchestrated operation that involved private aircraft and tens of millions of dollars.

Bruno Vekaric, a top adviser to Vladimir Vukcevic, Serbias chief war crimes prosecutor, declined to identify the alleged recipients but said the information came from people involved in the operation, including former members of the now-disbanded Kosovo Liberation Army.

Vukcevic showed the AP a thick blue binder jammed with documents he recently handed over to Marty. He declined to let AP review the statements, citing the need to protect the identities of Albanian informants.

KLA guerrillas fought Serbian troops loyal to the late strongman Slobodan Milosevic in a conflict that claimed at least 10,000 lives. The bloodshed ended after NATO pummelled Serbia with airstrikes and sent in peacekeepers in June 1999. Kosovos ethnic Albanian leaders declared independence in February 2008.

The alleged organ harvesting reportedly happened in the confusing weeks that followed the wars end a time when hundreds of thousands of ethnic Albanians who had sought refuge in neighbouring Albania were streaming back into Kosovo.

Serbian officials say up to 400 Kosovo Serbs vanished without a trace during that period, and some fear a few dozen may have fallen victim to an organ operation.

Albanian and Kosovar authorities vehemently deny that Serbs were killed and their organs harvested. In an interview with the AP, Kosovo Prime Minister Hashim Thaci himself a former KLA commander who once went by the nom-de-guerre The Snake dismissed the allegations as a complete fabrication.

But Serbia is pressing Albanian and international authorities to take another look at the house, as well as at maps and other intelligence it claims detail the locations of three mass graves in northern Albania sites that Serbia suspects may contain the remains of missing Kosovo Serbs.

Vekaric told the AP his office has obtained statements from ex-KLA rebels confirming they had access to Albanian military clinics in the area, as well as testimony from two Serbs who escaped prison camps run by the KLA in northern Albania and said the rebels operated medical clinics in the area.

He said Serbian prosecutors also have the bank account details of individuals who profited from sales of organs, narcotics and weapons trafficked through Kosovo and northern Albania, along with photos of surgical scissors allegedly recovered from the house.

From the start, the investigation was stymied by international officials insistence that neither the U.N. mission in Kosovo nor the tribunal in The Hague had jurisdiction over crimes committed in Albania, former U.N. forensics expert Jose Pablo Baraybar told the AP.

Del Pontes book, meanwhile, appears to have embarrassed the government of Switzerland, which now employs her as its ambassador to Argentina. It barred her from attending her book launch, calling it incompatible with her current duties.

Albanias prosecutor-general, Ina Rama, declined numerous requests to be interviewed. But two of her predecessors, Theodhori Sollaku and Arben Rakipi and Fatos Klosi, a former chief of Albanias secret police insisted the allegations are speculative at best and Albania has nothing to hide.

New York-based Human Rights Watch has been conducting its own investigation into the allegations. The group pressed Kosovo and Albania to reopen the case and sent letters to both nations prime ministers last spring. They went unanswered.

I really dont know why this wasnt taken more seriously, said senior researcher Fred Abrahams. The evidence and allegations are credible.

Officials acknowledge the Balkans is a hotbed for organ trafficking.

In November, Kosovo police raided a clinic in the capital, Pristina, where they arrested two ethnic Albanian doctors suspected of illegally removing a kidney from a Turkish donor and transplanting it into an elderly Israeli mans body. Authorities are still searching for a third doctor, also a Turk.

Medical experts say that although transplantation requires a large team of surgeons and sophisticated equipment, the simple harvesting of a kidney or liver can be fairly straightforward. But speed is of the essence, and the allegations that remote northern Albania may have been used to harvest highly perishable organs raise questions.

Roads are unpaved and so badly rutted that villagers without four-wheel drive vehicles travel by mule. That suggests a helicopter would have been needed to whisk an organ out of rugged northern Albania to Tiranas international airport, where it presumably would be flown onward to a recipient in the West.

In February 2004, Baraybar led a team of investigators to the house in Rripe. The investigators, accompanied by a local Albanian prosecutor, sprayed a chemical agent on the floors and walls. That revealed two sizable splatters of blood: one in the kitchen, another in a storage room.

My gut feeling is that something happened there, Baraybar said.

Yet forensics tests were never conducted on the stains to determine if the blood was human or animal.

Outside the house, on a steep slope leading down to a stream, Baraybars team recovered syringes; empty containers of Tranxene, a muscle relaxant, and chloraphenical, an antibiotic; a piece of gauze similar to material used for surgical scrubs; and an empty handgun holster, according to the investigative report. It does not mention the surgical scissors Serbia alleges also were found.

When the team tried to speak to villagers, the local prosecutor answered for them, Baraybar said. And when investigators attempted to dig in a nearby cemetery which they were told might hold Serb remains, a mob quickly formed to drive them away.

It was quite a hostile situation, he said.

It still is: When AP journalists turned up recently at the house, elderly owner Abdulla Katuci was enraged.

Unshaven, sporting a black leather chauffeurs cap, a threadbare tweed jacket and a white mustache, he waved his arms and bellowed: How could we perform surgery here? Theyre all lies!

Katuci said no Kosovars of any kind Serbs or Albanian guerrillas ever set foot on his property. He said the syringes and pill bottles recovered at the site were items his family used to provide their own medical care. The bloodstains, he said, came either from babies delivered in the home over the years, or from chickens and lambs prepared for dinner.

The Hague tribunal should come here and check it out, and call us all as witnesses, he said.