The indictment in Germany against a young Syrian national, identified only as Mohammad A. in line with German privacy rules, was filed at a Berlin court earlier this month.
Federal prosecutors said in a statement that he is accused of supporting a foreign terrorist organisation and preparing a serious act of violence.
Prosecutors said that the suspect supported the ideology of the Islamic State group and that, between mid-July and August last year, he was in contact with a young man in Austria who planned to attack a Taylor Swift concert in Vienna.
He allegedly helped by translating bomb-building instructions from Arabic and organising online contact with an IS member abroad, among other things.
The suspect also allegedly gave his acquaintance in Austria the text for an oath of allegiance to IS, which the latter used to join the group.
He is not in custody, prosecutors said. The court must now decide whether to bring the case to trial and when.
