Pic shows: Alternative cancer healer Klaus Ross. As many as 70 people may have been poisoned to death by a treatment centre offering alternative therapy to cancer patients. The clinic of the German natural healer Klaus Ross in the western German town of Brueggen has been temporarily closed pending investigation. According to German reports, prosecutors are now investigating 70 suspicious cases of deceased patients who were treated with Bromopyruvic acid, a substance said to kill cancer cells but also described by some doctors as "potentially highly poisonous" and "not yet fully researched." The legal team are trying to find out if the deaths were caused by cancer or by the administering of the substance. Three patients at the clinic died between 25 and 27 July, with two others needing emergency treatment in a hospital. They were all given Bromopyruvic acid, which sparked the inquest. Reports suggested some of the 70 bodies would most likely need to be taken out of their graves in order to find out the real cause of death. The clinic which is located close to the border of Belgium and the Netherlands, was popular with patients in both Germany and across the border who had been told normal medical treatment would not be able to heal their cancer. Klaus Ross, a technician who sold medical appliances, was schooled as an alternative biological doctor, according to a report in Dutch media. He had a licence to administer injections and intravenous therapy. The treatments of the centre included cancer therapy, pain-reducing therapy and drug addiction treatment. A ten-week course of treatment for cancer patients costs almost 10,000 EUR (8,630 GBP). (ends)