Between 2000 and 2013, 850 asylum-seekers were asked by the German Federal Intelligence Service (BND) and the Federal Office for the Protection of the Constitution (BfV) to provide security-related information, according to the report from German newsmagazine "Spiegel."

Staff from a subsidiary of the BND that was specifically in charge of "foreigners' affairs" in Germany - the HBW - were among those to interrogate asylum-seekers, "Spiegel" said.

Although the HBW was closed in June 2014, security sources say people seeking refuge in Germany are still being pushed to provide information on a "voluntary" basis, security insiders have told German media.

'Questionable practice'

The "Spiegel" said that the practice was controversial, as refugees were often offered a protected status that they would not have received if they had refused to cooperate. It said potential informers might also have been recruited with the promise of legal privileges.

The information contained in the "Spiegel" report came in response to a question posed in parliament by the Left party, which criticized the use of asylum-seekers for intelligence purposes.

"If intelligence agencies repeatedly put refugees under pressure, it is not just morally reprehensible: The truth of the information thus acquired must also be called into question," Left parliamentarian Martina Renner was quoted as saying.