Berlin: A Syrian passport found next to a suicide bomber in the Paris terror attacks may have been planted, German Interior Minister Thomas de Maiziere said.

Reports that the identity in the passport may have been registered in several countries along the so-called Balkan route raise the suspicion that it could be a deliberate attempt to implicate refugees and "make people feel unsafe", Mr de Maiziere.

Photo from Greece's migration policy ministry shows a document issued to 25-year-old Ahmad Almohammad. Credit:AP

"There are indications that this was a planted lead, but it still can't be ruled out that this was indeed an IS terrorist posing as a refugee," he told reporters in Berlin on Tuesday, referring to Islamic State, which France blames for organising the violence.