"The Foreign Ministry has received this information, but it has not yet been verified. We have passed it on to our embassy in Washington, which is trying to check in the State Department whether or not it is correct," Vinko Ljubicic, who heads the Foreign Ministry task force monitoring events in Iraq, told Hina on Thursday.
Asked about the source of the information, Ljubicic said it had come from Mikulic's colleagues, truck drivers from Croatia.
There has been no official explanation of Mikulic's arrest, but there has been speculation in the media that he was arrested by Americans because he had been filming from his truck US military bases and the route he was using.
Abu Ghraib is a huge prison compound situated in a Baghdad suburb where Saddam Hussein used to settle accounts with his opponents. It gained international notoriety after information and pictures of Iraqi prisoners of war being ill-treated by US soldiers had leaked to the public.