Nato troops broke into a family home of detained former Bosnian Serb leader Radovan Karadzic and questioned his wife and children as part of their search for war crimes fugitive Ratko Mladic, the alliance said today.
Mladic, Karadzic's wartime military chief, was indicted along with the political leader for the 1995 Srebrenica massacre of 8,000 Muslims and the 43-month siege of Sarajevo.
Although Karadzic was arrested in Belgrade in July after 13 years in hiding, Mladic is at large and believed to be hiding in Serbia.
In a morning raid, Italian carabinieri assisting Nato operations in Bosnia searched the house where Karadzic's wife Ljiljana lives in the town of Pale, a Nato spokesman said.
"We have strong grounds to believe that the support network that allowed Radovan Karadzic to remain at large until his arrest and also the support network of Ratko Mladic ... are in fact connected. They do have contact," said the spokesman, Derek Chappell.
"We believe that there had been communication between certain members of Karadzic's family and members of Mladic's support network," Mr Chappell said.
Nato has conducted several raids on the Karadzic family home in the past few years.
Mr Chappell said Nato interrogators interviewed Karadzic's wife, son and daughter, and searched the house for evidence. But, he declined to say if any material had been seized.
Karadzic is now awaiting trial at a United Nations tribunal in the Hague.
Mladic's arrest is seen as a key condition for Serbia's closer ties with the European Union.