The Croatian authorities have issued an international arrest warrant for former Prime Minister Ivo Sanader, soon after he left the country amid a corruption inquiry.
Mr Sanader crossed into Slovenia on Thursday, hours before parliament voted to lift his immunity from prosecution.
He has been linked with various criminal cases during his time as prime minister from 2003 until 2009.
Mr Sanader reportedly denied fleeing from prosecution.
The Croatian authorities submitted the arrest warrant to Interpol overnight, requesting that Mr Sanader return to face charges.
The BBC's Balkans correspondent, Mark Lowen, says the timing of Mr Sanader's departure prompted the Croatian press to question whether he received a tip-off that his arrest was imminent.
Croatian President Ivo Josipovic described the departure as "a big defeat of the system".
"This case is an example that will show whether the system of responsibility in Croatia is functioning or not," he said.
Mr Sanader stepped down as prime minister in July 2009 in a surprise move.
He was expelled from the HDZ party in January but carried on as an independent MP.
It is unclear whether he is still in Slovenia but late on Thursday a lawyer claiming to represent him said the former prime minister was on a scheduled business trip and would return to Croatia "within the next three or four days".
Croatia is under pressure to show it is tackling corruption to reach its goal of joining the European Union.