HAMBURG (AFP) - Investigators searching for the source of a killer bacteria were attempting to track supplies made to a north German restaurant, the German media reported on Sunday, as the death toll climbed to 22. All but one of the deaths occurred in Germany, the source of the enterohaemorrhagic E. coli (EHEC) outbreak which has affected 12 countries. The other victim died in Sweden. Joachim Berger, the owner of the 'Kartoffelkeller' restaurant in the Baltic seaport of Luebeck, told ZDF public television that health inspectors had carried out tests at the premises after three separate groups fell ill after eating there.