Investigative journalist Yassin Musharbash, a reporter with the German newspaper Die Zeit, was the first to report on the documents.

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The article added, however, that the victims were being done a disservice by their "self-publicizing" lawyers, a criticism endorsed by the weekly Die Zeit.

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The weekly Die Zeit recently argued that, whatever the risks of an underestimate, one should also not overestimate what the chancellor can do, at least with her present coalition.

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According to Die Zeit, the reason the letter was relayed to the Germans was because al-Mauretani mentions a Moroccan in the document with exactly the same date of birth as Abdeladim el-K, who prosecutors claim was the ringleader of the alleged Dusseldorf cell and trained with al Qaeda in Pakistan in 2010.

CNN: March 20, 2013 -- Updated 1211 GMT (2011 HKT)