In accordance with international legal assistance legislation, the request has been sent together with the documentation translated in German which explains the charges against Sanader, the spokesman told Hina.
In the event that Austria grants the request, Sanader will be interrogated by Austrian investigators, Djuricic said, adding that USKOK also requested that its investigators be present at the questioning and allowed to ask questions.
Under the new criminal proceedings legislation, neither suspects nor their defence lawyers are allowed to see the investigation file before the suspects are interrogated by investigators.
Sanader's lawyers believe that the condition to see the file on their client was met as soon as he presented his defence at a questioning in Austria in late December 2010, when he said that he did not feel guilty of what Croatia is accusing him.
Therefore the lawyers representing the former premier have filed a motion with the USKOK to see the file on their client, enclosing the documentation from that hearing in Austria.
The Zagreb County Court said on Tuesday that the motion could be considered next week.
Sanader has been in extradition custody in Austria since December 10 on a warrant issued by Croatia on suspicion of corruption.
In the meantime, Austrian authorities have also launched an investigation into him on suspicion of money laundering via a Tyrolean bank.
He has said in an interview with the Salzburger Nachrichten newspaper that he will not agree to a simplified extradition procedure until he is fully informed of what he is being accused of in Croatia.
"My lawyers in Zagreb have still not been given access to the file, so I don't know the details of what I'm being accused of. Until that is the case, I certainly won't agree to a simplified extradition procedure," Sanader said in the interview which was published last weekend.