The Jewish human rights organization on Friday said the Baden-Baden state court judge in charge of the case had disallowed German police requests on several occasions for telephone taps of Heim's relatives and an old friend who had been in contact with the fugitive.

But Heinz Heister, presiding judge and spokesman for the court, said that in the case of the friend, there had been no appeal of the court's decision, and that the only time a decision disallowing "investigative measures" was challenged, the Baden-Baden court's ruling was upheld.

"Investigative measures — even in the case of a person urgently suspected of many counts of murder — are held to certain boundaries by the constitution and the laws," Heister said in a statement.

Heim, 94, was known for his sadism as a doctor at the Nazi's Mauthausen concentration camp. He was able to flee before authorities came to arrest him in the southern town of Baden-Baden in 1962, however, and his whereabouts today remain unknown.