Germany's BND spy agency spied on European politicians and enterprises at the behest of the NSA for over a decade.

Der Spiegel reports (in German) that for years the NSA sent its counterparts at the BND (Bundesnachrichtendienst – Germany's Federal Intelligence Service) thousands of so-called selectors – IP addresses, emails, and mobile phone numbers – it wanted targeted for online surveillance.

German cyberspies fed this data into their own surveillance systems. The reports generated were evaluated at BND headquarters before intelligence was passed back to the NSA.

In practical terms, it seems that the BND have been tapping the Internet Exchange Point DE-CIX in Frankfurt, since at least 2009.

Results from the bulk tap of this Internet exchange were then passed over, in part at least, to the Americans as part of a collaborative agreement involving intel agencies.

The selectors included referred to European politicians and European aerospace and defence firms, including the European Aeronautic Defence and Space Company (EADS) and Eurocopter.

BND workers picked up on this anomalous targeting – which had nothing to do with a bilateral US-Germany agreement signed in 2002 to pool efforts in combating global terrorism – and have been complaining about it since at least 2008.

Yet it was only when the Edward Snowden revelations began in 2013 that German spy bosses began questioning the practice, which fits more closely with the profile of economic espionage.

An estimated 800,000 selectors were passed from the NSA to the BND in total over the years. A post-Snowden internal probe concluded that at least 2,000 of these various spying requests were contrary to either German or wider EU interests.

The BND helped the NSA with spying on European ministers and enterprises, without anyone in the German parliament being aware of this.

BND bosses didn't pass on their findings to the Chancellor's Office instead acting only to ask the NSA not to filter out requests that potentially ran contrary to German and Western European political and economic interests.

Once the German parliament got wind of the NSA-led snooping, the BND was asked to re-examine its figures before concluding that 40,000 selectors were directed against EU and German interests.

The exposure of the practice has re-ignited another huge political row about spying in Germany, as De Welt reports.

The controversy risks inflaming already strained relations between Berlin and Washington. Germany is still in the process of healing from last year's revelations of mass surveillance of German citizens by the NSA, and (more particularly) US snooping on German Chancellor Angela Merkel's mobile phone.

Last year allegations emerged that a German spy agency staffer spied for NSA during a parliamentary probe into NSA spying. ®