A killer jailed for 12 years after stabbing a nurse to death in a former Nazi concentration camp is facing a retrial after a court ruled his sentence was too lenient.

Bianca Simon, 26, was stabbed seven times in the throat, neck, and back with a chisel in the camp bunker near the German capital, Berlin, on 15th July 2021.

The trial judge said her killer – her ex-boyfriend, named only as 29-year-old Kurt L. under local privacy laws – had stabbed her repeatedly with “intent to kill”.

But he was only convicted of manslaughter because under a quirk of local law, any murder conviction requires proof of premeditation and malice.

Now Bianca’s killer is facing a retrial after Germany’s Federal Court of Justice (BGFH) declared the verdict and sentence too lenient on Wednesday, 22nd March.

Bianca’s body was found four days after her killing in a bunker that was part of the Sachsenhausen death camp used from 1936 until the end of World War II.

It mainly held political prisoners throughout the war, including Joseph Stalin’s eldest son Yakov Dzhugashvili.

The victim’s corpse was found shirtless and face-down in the corridors of an SS communications bunker.

The police later arrested woodworking technician Kurt L., who was the victim’s boyfriend, on 27th July 2021.

Two days before her killing he was overheard saying he would “make life hell” for Bianca because she had cheated on him.

Neuruppin Public Prosecutor Marc Reinhardt, 35, had demanded life imprisonment for the killer after autopsy results showed Bianca had died violently.

But at his trial 13 months ago, Judge Udo Lechtermann, 67, reportedly did not see any “maliciousness” in the violent act.

He argued that no “murder criteria” had been fulfilled, and he refused the public prosecutor’s demand for life imprisonment.

Under German law, “murder” requires premeditation, and the judge did not accept that this had been proven.

It is currently unclear when the retrial will take place.