A Belgrade court on Sunday ruled that Cedo Colovic, a 57-year-old citizen of Croatia and Serbia arrested in Belgrade on Friday on suspicion of spying for Croatia, should remain in custody for 30 days.
The court made the decision on the basis of a motion by the prosecution, court spokesman Tanja Koljensic said.
Earlier in the day, after Colovic was questioned, the prosecutors launched an investigation into him and requested that he be placed in custody because he was a flight risk and might tamper with witnesses or repeat the crime he was suspected of.
According to reports in the Serbian media, Colovic is a former officer of the Croatian Serb rebel army, born in Drnis, Croatia, and holding Croatian and Serbian citizenship.
The Serbian prosecutorial authorities said earlier that Colovic had worked and lived in Croatia until 1990 and that he later took up residence in Serbia.
Commenting on the case, a former director of the Serbian Military Intelligence Agency (VBA), Momir Stojanovic, told the Belgrade media that it was important to establish which information Colovic had divulged to Croatia and who his helpers were.
Relations between Croatia and Serbia are very complex and this arrest will definitely not contribute to their stabilisation, Stojanovic told the Politika daily.
The news of the arrest comes at a time when diplomatic relations between Croatia and Serbia are very much strained, primarily because of a Serbian law on universal jurisdiction which enables Serbian authorities to prosecute Croatian citizens for war crimes committed in Croatia's territory against Croatian citizens.