Oskar Groening Auschwitz trial Lueneburg
Former Nazi SS officer Oskar Groening, dubbed the "bookkeeper of Auschwitz", sits in a courtroom in Lueneburg, GermanyReuters

German prosecutors are seeking a three-and-a-half-year prison sentence for the so-called "Bookkeeper of Auschwitz", who is currently on trial and accused of being involved in the killing of 300,000 Jews.

Oskar Groening, 94, was deployed at the Nazi concentration camp between 1942 and 1944. He was reportedly tasked with taking jewellery, money and other valuables away from those being sent into Auschwitz before sending them on to Berlin.

He is also accused of being on "ramp duty" at Auschwitz, whereby he allegedly processed those arriving by train at the death camp before deciding who should get sent straight to the gas chambers.

Groening is on trial in Lueneburg accused of more than 300,000 counts of accessory to murder because of his role at the concentration camp in Nazi-occupied Poland.

He admitted he had a "moral guilt" over his past, and repeatedly apologised to victims, but said it is up to the court to rule whether he is legally culpable for the deaths.

During his closing arguments, public prosecutor Jens Lehmann said that while Groening was a part of a "nearly incomprehensible" number of killings, he himself had "limited contribution" to their deaths.

Lehman added the court should consider whether Groening has already served some of his sentence haven being investigated for his crimes since the 1970s.

Prosecutors argued Groening should have between 14 and 22 months deducted from his sentence after he was not given a speedy trial after authorities shelved the case against him in the 1970s.

Up to 15 years behind bars

Groening, whose health issues has led to several delays in the proceedings, could be sentenced to 15 years in jail in a trial that has ignited a debate on the merit of handing prison sentences to elderly, frail, former Nazis.

Earlier in July, Holocaust survivor Irene Weiss, 84, told the court she could not forgive Groening for his part in the mass killings.

"He has said that he does not consider himself a perpetrator but merely a small cog in the machine," she said.

"But if he were sitting here today wearing his SS uniform, I would tremble and all the horror that I experienced as a 13-year-old would return to me."

In a statement read out in court, Groening said he can "only ask my God for forgiveness".

"I had no idea about the terrible conditions during the deportations – that shocked me," the statement added, according to AFP. "It also became clear to me how much Auschwitz and the Holocaust influenced the lives of the witnesses I heard here. They have obviously suffered their whole lives from their experiences in Auschwitz and the loss of so many loved ones."

The verdict for the trial, expected to be one of the final ones for Nazi war crimes, is expected by the end of July.