An ex-nurse convicted of murdering 10 patients in western Germany may be linked to more than 100 additional deaths, an official has said.
The chief public prosecutor in Aachen, Katja Schlenkermann-Pitts, told the BBC that there was "a correspondingly high number of suspicious cases" under review.
She cautioned that the cases represented preliminary suspicions and that some could be dismissed following forensic examination.
In November last year, a regional court in Aachen convicted the former palliative care nurse, who has not been publicly named, of 10 counts of murder and 27 counts of attempted murder, sentencing him to life imprisonment.
The court found that during night shifts at a hospital in Würselen, the man had administered excessive doses of sedatives and painkillers to seriously ill patients without medical justification.
