A German nurse serving a life sentence for murdering two patients may have killed up to 84 more, police say.

Niels Hoegel, 40, was jailed in February 2015 for killing two intensive care patients at the Delmenhorst hospital near the northern city of Bremen.

His crimes came to light after he was convicted of attempted murder in another case, which led authorities to investigate hundreds of deaths and exhume bodies of his former patients from Delmenhorst and the nearby Oldenburg hospital.

Prosecutors have always believed he killed more people, putting the estimated figure at 43 in 2016.

However, police now say investigators exhuming and analysing more bodies have found evidence of "84 more murders", which would make Hoegel one of Germany's worst ever serial killers.


And the number could be even greater as some suspected victims were cremated, prosecutors say.

Hoegel would inject patients with an overdose of unprescribed heart medication in order to revive them and show off his nursing skills, a court heard during his initial trial.

He reportedly said he felt overjoyed when he received praise for bringing a patient back from the brink of death.

Oldenburg police chief Johann Kuehme said: "Eighty-four killings... leave us speechless.

"And as if all that were not enough, we must realise that the real dimension of the killings by Niels is likely many times worse."

Authorities are pursuing criminal cases against former staff as they believe many of the deaths could have been prevented "if the people responsible at the time" had been quicker to alert authorities.