The security services suspect that members of the detained family are part of a terrorist cell, according to the Bild newspaper. However, the detainees were released a few hours later.
"All members of this family are under suspicion that they have long been raising money for the Daesh* terrorist organisation and thereby supported terrorists", police spokesman Ulrich Fassbender told the newspaper.
Those detained include men and women between 19 and 58. Seven of them have German passports, but are of Balkan origin. One of the suspects is a Bosnian. At the moment, the police reportedly have no data that the detained family itself plotted a terrorist attack in Germany.
The suspects are supposed to be questioned later in the day, and then a decision will be made on their placement in a detention centre.
*Daesh (also known as ISIS/ISIL/IS) is a terrorist group banned in Russia