He was later acquitted of war crimes charges by a Bosnian court but convicted of financial offices in a separate trial and issued a five-year prison sentence.
Following the end of the Bosnian War, he set up the bank Privredna Banka Sarajevo and the company ManCo, both of which were frequently accused of questionable financial practices.
[8] Mandić was appointed as the Republika Srpska's deputy interior minister in September 1997, reportedly at the instigation of Momčilo Krajišnik and his allies.
Mandić denied the accusation, saying, "I wish Radovan Karadžić health and happiness and I hope he will never be caught, but as far as financial assistance is concerned, these allegations are simply not true.
"[13] This notwithstanding, Mandić's financial assets were subsequently frozen by various international agencies,[14] and the United States Department of State described him as "a major funding source for Radovan Karadžić through [his] control of an elaborate network of criminal enterprises engaged in embezzlement, business fraud, fictitious loans, and various other activities that generate funds to financially support the protection of Karadžić.
[16] Mandić was arrested by Serbian officials in April 2003 on suspicion of having committed a number of criminal acts; this occurred in the aftermath of Zoran Đinđic's assassination and in the context of a large-scale crackdown on organized crime.
[17] In July 2003, the Second Municipal Court in Belgrade announced that Mandić was being investigated on suspicion of having overseen up to six million euros' worth of illegal transactions from the Federal Republic of Yugoslavia into Bosnia and Herzegovina between November 2002 and March 2003.
In the same interview, he said that he was no longer a supporter of the Serb Democratic Party and that the net worth of his business holdings had been reduced from several millions to several hundred thousand euros.
[21] In November 2004, High Representative for Bosnia and Herzegovina Paddy Ashdown liquidated the Privredna Banka Srpsko Sarajevo, of which Mandić was managing director.
[31] In July 2006, he was charged with having been "exclusively responsible [in his capacity as justice minister] for the functioning of the correctional facilities in the Serb Republic between May and December 1992" when three prisons (two near Sarajevo, the other in Foča) were used as detention camps where non-Serbs were illegally imprisoned and treated harshly.