Mr Sanader is now an independent MP Police in Croatia say former Prime Minister Ivo Sanader has left the country as MPs prepare to vote on removing his immunity from prosecution.
Parliament’s immunity commission is due to take a vote as early as Thursday after a request from prosecutors, commission spokesman Arsen Bauk said.
A corruption inquiry is focusing on officials from the ruling HDZ party who were in office under Mr Sanader.
Brussels has put pressure on EU hopeful Croatia to stamp out corruption.
Mr Sanader stepped down as prime minister in July of last year in a surprise move and was expelled from the HDZ in January.
As an independent MP, he still enjoys immunity from prosecution.
A police spokesman was quoted as saying that the former prime minister had crossed into Slovenia on Thursday and police had no legal reason to stop him.
Media reports said he had Austrian citizenship.
“The request for lifting Sanader’s immunity has arrived, after which the relevant court will decide on his possible detention,” Mr Bauk said without giving further details.
On Monday, former Defence Minister Berislav Roncevic, who served in Mr Sanader’s cabinet in 2003-07, was sentenced to five years in prison for corruption on Monday.
Since Mr Sanader’s departure from office, a dozen managers of banks and state companies have been arrested for corruption but in most cases indictments are still pending, Reuters news agency reports.
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