General Ant Gotovina is wanted by the war crimes court at The Hague, but Sanader on Tuesday said he did not want to have a "duel" with UN chief war crimes prosecutor Carla Del Ponte over the issue.
"We are investigating all the information we get. When we get relevant reliable information we will share this with the EU task force and with the chief prosecutor," Sanader said.
The Croatian leader made the comments after the European Union, which delayed the planned start of talks last month due to Croatia's lack of cooperation, confirmed it still cannot give Zagreb a green light.
"So far, we don’t have any information which could lead to the fact that he is in Croatia," the prime minister added.
"We are investigating all the information we get. When we get relevant reliable information we will share this with the EU task force and with the chief prosecutor"
Croatian prime minister
The affirmation came barely an hour after the UN chief war crimes prosecutor said she still believes Gotovina is in Croatia, crossing from time to time into Bosnia-Hercegovina.
"We have come here not to have a duel or to have a fight with Carla Del Ponte but to work together…because we have the same goal: Gotovina has to stand trial in The Hague," he said.
"I hope that we can start negotiations as soon as possible," Sanader said.
Gotovina is charged by the International Criminal Tribunal for the former Yugoslavia over alleged war crimes against ethnic Serbs at the end of the 1991-95 Serbo-Croatian war. Zagreb has long insisted it has no knowledge of his whereabouts.