According to a report in news magazine Der Spiegel, the German interior ministry stopped passing on information to the US that could lead to the location of German citizens, after last October's deadly attack.
The attack killed three young Islamists in a Taliban camp in the border region of Waziristan. One of them, Bünyamin E., was a German citizen.
Several German courts are investigating the charge of aiding and abetting Bünyamin E.'s murder, some of which are directed at the US secret service, the CIA. Allegations have also been directed at the German secret service, the BND, which reportedly supplied information that led the US to the Islamists.
According the magazine, since this attack, BND information is supplied to the CIA with the caveat that it can only be used to arrest and not kill suspected terrorists who are also German citizens.
At the time of his death, Bünyamin E. was 20 years old and was already under BND surveillance. He had received military training in an Islamist camp in Uzbekistan and was under investigation by the German police on suspicion of preparing a terrorist attack.
Since 2001, all information about suspected terrorists has been routinely passed on to the US.
It is unclear whether a police investigation into the death of Bünyamin E. will be carried out, but under German law, if any German citizen dies by a violent act in a foreign country, the German authorities must investigate it.