However, a friend of Sanader, Jerko Rosinsaid, said on state-run TV Friday that the former leader was on a foreign business trip and would cut it short to return home. An Internet portal, t-portal.hr, reported that Sanader has hired a lawyer in Zagreb.
Police spokesman Krunoslav Borovec told The Associated Press on Friday that the warrant for Sanader
-- who is now a lawmaker -- was issued overnight and sent to Interpol.
Once hailed at home and abroad for uprooting the nationalism that reigned in Croatia in the 1990s and making it pro-Western, Sanader is now technically a fugitive. Biographical information and his photo appeared on a police list of wanted persons Friday, and police searched his home.
Sanader, who abruptly quit as prime minister on July 1, 2009, left Croatia on Thursday morning without problem since there was no warrant for him at the time.
He has a company in Austria and has visited the United States to speak at Columbia University's Harriman Institute, which focuses on countries of the former Soviet Union, East Central Europe and the Balkans.
Sanader -- the highest-ranking official to be charged for a crime since Croatia became independent in 1991
-- was last seen driving into neighboring Slovenia on Thursday morning.
In Croatia, a lawmaker can be sought, detained and prosecuted after he's stripped of immunity. Parliament lifted Sanader's immunity Thursday afternoon.
Croatia's Office for Suppression of Organized Crime and Corruption said Sanader is suspected of conspiring to commit crime and abuse of office. It did not disclose details of the ongoing investigation, but at its request Zagreb district court ordered Sanader's 30-day detention.
Several former government officials and businessmen -- including Sanader's closest allies as prime minister
-- have been jailed as Sanader's successor, Prime Minister Jadranka Kosor, works to fight high-level corruption. That goal is a key condition for Croatia's entry into the European Union. Croatia hopes to join the bloc in 2012.