German authorities say their analysis of dirt found in a suitcase belonging to Nazi fugitive and concentration camp doctor Aribert Ferdinand Heim, confirms the man known as "Doctor Death" spent "considerable time" hiding in North Africa, and probably in Cairo. Though witnesses, including Heim's Cairo doctor and members of his family, told The New York Times that he died of rectal cancer in 1992, Dr. Efraim Zuroff, the director of the Simon Wiesenthal Center's Jerusalem office, told The Jerusalem Post on Sunday it was far from certain that Heim was dead. Heim is accused of killing and torturing inmates of concentration camps - including Buchenwald, Sachsenhausen and Mauthausen. He allegedly conducted medical experiments on prisoners, tested the efficacy of various lethal injections to the heart, and removed organs from prisoners without using anesthesia. Tipped off that police were prepared to arrest him, Heim fled Germany in 1962. Though some Nazi-hunters, including Zuroff, believed Heim was hiding in Chile, some witnesses said that after his escape he moved through European countries before settling in Cairo, where he allegedly changed his name to Tarek Hussein Farid and converted to Islam. In a statement released on Friday, German police said that along with other substances linked specifically to North Africa, traces of the mineral lime, in a form which only existed in Cairo, were found in Heim's suitcase, confirming his presence there. The suitcase, apparently discovered by owners of the Kasr el-Madina Hotel in Cairo where Heim lived, contained letters and financial and medical records, which the German police said indisputably linked the suitcase to Heim. But Zuroff told the Post that while he did not doubt the German police's findings, the analysis had done little to determine whether Heim was still alive. "This case is far from a closed," said Zuroff. "He might have died in Cairo, but there is no way to corroborate that. If we were to accept the evidence as it has been presented until now we would not be doing our jobs." According to the German report, officials in Cairo issued a certified copy of a death certificate under his alias. But the police have been unable to confirm that the certificate referred to Heim. "At what point concrete results can be expected is not yet clear," the police statement said. While the analysis represented another step toward discovering the complete story of Heim, the book would remain open until investigators find his body, Zuroff told the Post. "These findings help, but it's not the main issue," Zuroff said. "The main issue is to find his body. Until then we are unable to verify this version or any version of the events."