* Tapes said to feature Kosovo PM and senior officials
* Kosovo government condemns "blackmail and sabotage"
* Tapes part of graft probe targeting politicians -sources
Kosovo's government has condemned the leak of tapped phone calls recorded by European Union crime investigators and featuring voices identified as that of the prime minister and several senior officials.
EULEX, which oversees law and order in Kosovo and handles cases of organised crime and war crimes, said the audio tapes were part of a continuing case and had been handed over to defence lawyers and Pristina district court.
EULEX did not specify the nature of the case or who was involved. But political sources said they were aware of a corruption inquiry involving senior political figures. An international security source said: "The recordings are part of a corruption investigation into the ministry of transport."
The audio files appeared on YouTube on Thursday, in what the EU's police and justice mission in Kosovo (EULEX) said was "a serious breach of confidence".
"It is unfortunate that some parties have improperly released this material into the public domain," the mission said in a statement late on Thursday.
Kosovo's government, led by Prime Minister Hashim Thaci, denounced the leak as "scandalous" and the phone-tapping as illegal.
"These actions represent a direct effort on the part of both domestic and international mechanisms to blackmail and sabotage leaders of the Kosovo institutions and the normal functioning of our state," the government said in a statement.
A voice identified on the YouTube post as Thaci's is heard twice in the five audio files, all of which appear to feature Adem Grabovci, head of the parliamentary caucus of Thaci's Democratic Party of Kosovo.
Kosovo continues to struggle with deep-rooted organised crime and corruption almost five years since it declared independence from Serbia with the backing of the West.
The phone-tapping affair emerged a week after the Supreme Court, chaired by an EULEX judge, ordered the retrial of Fatmir Limaj, a close ally of Thaci, for war crimes, over the objections of the government.
Limaj was acquitted of war crimes in May after the chief prosecution witness killed himself and his written testimony was ruled inadmissible. The Supreme Court overturned that decision.
The charges against Limaj have to do with a detention camp run by ethnic Albanian guerrillas in Kosovo during the 1998-99 war with Serbian security forces.