London- A German nurse jailed for murdering two patients is suspected of killing at least 84 other people, investigators said on Monday.

Niels Hoegel, 40, was jailed in February 2015 for two murders and four counts of attempted murder or causing bodily harm on intensive-care patients at the Delmenhorst hospital near the northern city of Bremen.

Hoegel has “confessed in many of those cases”, a police statement said, but could not remember all the details of his actions. If confirmed, the death toll would be among the worst ever compiled by a German serial killer.

Hoegel has admitted to injecting patients with drugs that can cause heart failure or circulatory collapse so he could then try to revive them and, when successful, shine as a savior before his medical peers.

After the revelations, police and prosecutors three years ago launched a special forensic commission to look into other patient deaths.

Presenting their findings, police said Monday that 134 bodies had been exhumed and tested for traces of the deadly drugs, and that police also reviewed scores of medical records and questioned hundreds of witnesses.

However, police explained that the cause of death in many cases could not be determined because the bodily remains had been cremated.