The Afghan kidnapper who took two German engineers hostage  has admitted for the first time that his men shot and killed Rüdiger Diedrich, who had been sick with heart disease, during a march into the mountains last summer.

Nissam Udin, the head of the band of criminals that kidnapped the men, described the killing of the German as the product of a misunderstanding. “He collapsed every time he walked for 10 minutes. We didn’t understand his situation,” Nissam said in an interview with SPIEGEL. Two of his fighters, he said, “two inexperienced friends,” misunderstood Diedrich, who he claims spoke several times of his suffering. “Our friends thought he was begging them to ‘shoot me,’ ‘shoot me’.”

Nissam, known in Afghanistan as Mullah Nissam, described himself as a member of the Taliban. “We want to eliminate the infidels,” he said, “first the Afghan infidels and then the foreign infidels -- until they leave our country.” Following the hostage-taking, the group armed itself and also upgraded its technology. Nissam said he had sent the $600,000 in ransom money sent by the German government to the “eldest in the group, as we have agreed amongst our Muslim brothers.” German and Afghan authorities, though, believe at least some of the money was funneled directly to the Taliban. Immediately after the payment of the ransom, according to information obtained by Afghan intelligence, Nissam traveled to the border area between Afghanistan and Pakistan, where he is likely to have delivered part of the ransom to the Taliban.

Investigators claim that one of Nissam’s confidants and accomplices in the kidnapping maintains close contact to the Taliban in the southern Afghan province of Helmand and Zabul and also to the so-called Quetta shura, the Taliban’s leadership council.

The investigation into the kidnapping band following Rudolf Blechschmidt’s release has been a slow one. Blechschmidt and Diedrich were kidnapped in Afghanistan by the criminal band last July 18. Charges have not yet been brought by German authorities against Nissam, and two suspects temporarily taken into custody -- Nissam’s grandfather and Kabul medicine student Abdul Wali -- have since been released. The only suspects still being held are four Afghan police who are believed to have participated in the kidnappings as well as two men suspected of having been minor players in the hostage-taking.