A nurse who is serving a life sentence in Germany for two murders may have killed more than 100 patients, prosecutors said.
Prosecutors and police in Oldenburg said they have completed examinations of patients who died during Niels Hoegel's time as a nurse at two local hospitals and have found a further 16 cases in which he is suspected.
In late August, they said they had determined that he might have killed at least another 84 patients beyond the ones for whose murder he is already serving time in prison.
Prosecutors have said that they expect to bring more charges by early 2018 against Hoegel, who gave patients overdoses of heart medication and other drugs because he enjoyed the feeling of being able to resuscitate them.
Hoegel was convicted in 2015 of two murders and two attempted murders at a hospital in Delmenhorst and was sentenced to life in prison.
During his trial, Hoegel said he intentionally brought about cardiac crises in some 90 patients in Delmenhorst because he enjoyed the feeling of being able to resuscitate them. He later told investigators that he also killed patients in Oldenburg.
Hoegel worked at the Oldenburg hospital from 1999 to 2002 and in Delmenhorst from 2003 to 2005.
Prosecutors said he is now suspected in 38 cases in Oldenburg and 62 in Delmenhorst, but that in five of those cases further examinations are needed.
As part of a wider investigation involving both hospitals, police and prosecutors reviewed more than 500 patient files and hundreds more hospital records. They also exhumed 134 bodies from 67 cemeteries, and questioned Hoegel six times.
Police have said that if local health officials had not hesitated in alerting authorities, Hoegel could have been stopped earlier.
Authorities are already pursuing criminal cases against former staff at the two medical facilities.