According to a press release from the US Embassy, Mikulic is being held in Camp Bucca near Umm Qasr, where the US forces keep foreign nationals, non-Iraqis.
Mikulic was detained for "allegedly collecting vehicle information and personal identification information beyond what is considered of general interest to tourists," the US Embassy said.
"It is a great thing that Mikulic is alive and well," Vinko Ljubicic, head of the Foreign Ministry task force monitoring developments in Iraq, told Hina.
Americans have said that Mikulic's case will be expedited and that it is presently under review by an official panel composed of Iraqis and nationals of other countries, Ljubicic said.
Camp Bucca, which currently holds nearly 4,000 detainees, is run by the US Army 800th Military Police Brigade.