Germany's domestic intelligence agency (BfV) has received more than 100 tip-offs that there are Islamic State fighters among the refugees currently staying in Germany, Berliner Zeitung
newspaper cited the agency's chief as saying.
The newspaper said on Friday, without citing its sources, that BfV chief Hans-Georg Maassen had recently mentioned this number at a discussion in the Interior Ministry with politicians who focus on domestic policy issues.
But Maassen also said that among those tip-offs there were some cases of untruthful defamation, the newspaper said.
The domestic intelligence agency was not immediately available to comment when contacted by Reuters.