According to Bavaria's state criminal police office, the 50-year-old suspect, a Bosnian national, was detained at Munich Airport.
The police said in a statement on Friday that the man is wanted by Bosnia for allegedly participating in torture and killings as a member of the police in the town of Ljubija.
However, police did not name him in the statement.
It added that the suspect was living in Munich, after being approached by Bosnian authorities via Interpol, the international police organization.
The man is now being held in a Munich jail awaiting a court decision on a Bosnian extradition request.