The former Prime Minister of Kosovo, Minister Ramush Haradinaj has been detained in Slovenia, because of an investigation looking into war crimes, during the Balkan conflict in the 1990s.
He was blocked from boarding a flight at Ljubljana Airport, his party reported.
Mr Haradinaj, who was previously been acquitted over war crimes charges from a UN Court, denies allegations that he guided campaigns of murder and torture against Serbs and their allies.
The former prime minister was detained as a result of an Interpol arrest warrant issued at the request of Serbia, related to alleged crimes committed during his time as a commander in the 1998-99 conflict.
The investigation into Mr Haradinaj’s involvement into the conflict of the late 1990s, is looking specifically at the death of at least 60 people.
His party have called on the police to allow Mr Haradinaj to travel freely.
"This unjustifiable act must not have any impact on our excellent relations with Slovenia," Kosovo Foreign Minister Hashim Thaci told parliament, according to Reuters.
"Slovenia is one of the more friendly nations we had in the most difficult of times."