A 96-year-old former secretary at a Nazi concentration camp has gone on trial in Germany for alleged complicity in the murder of more than 11,000 people imprisoned there, three weeks after she attempted to flee the proceedings.

Irmgard Furchner was pushed into the court in Itzehoe, northern Germany, strapped into a blue ambulance wheelchair and clutching a brown cloth bag. A silk patterned scarf, sunglasses and a medical mask covered her face.

Furchner, who was 18 when she started working at Stutthof camp in Nazi-occupied Poland as the secretary to its commandant, Paul Werner Hoppe, is being tried in a juvenile court due to her age when the alleged crimes were committed.

After trying to escape the trial in late September, leaving the retirement home in Quickborn where she lives and travelling by taxi to the outskirts of Hamburg, she was arrested several hours later and placed in police custody for five days before being fitted with an electronic wrist tag.

She was shielded by sheets as she entered the ambulance that brought her to the court on Tuesday morning. The trial has been moved to a prefab warehouse on the town’s outskirts to cope with the considerable interest in it and the extensive security involved.

When asked by the judge to do so, Furchner removed her headscarf and sunglasses and patted down her white hair. She spoke only to confirm her name and address and that she was widowed, but she was otherwise not willing to respond to questions from the court, according to Wolfgang Molkentin, her lawyer.

She looked on as the indictment was read out to the packed courtroom, appearing to listen. Occasionally she rubbed her face, clasped at the electronic tag on her left wrist and cast her gaze around the room through the glass screen erected to protect her from coronavirus infection.

The court heard how Furchner, born Irmgard Dirksen in 1925, worked as the chief secretary for Hoppe and in her administrative role “was contributory to the entire killing operation” at the camp.

Transport lists of detainees destined to be sent to Auschwitz to be murdered as well as radio messages, the dictation of Hoppe’s orders and his correspondence went through Furchner’s hands, according to the prosecution.

The court was told she would have “been aware of all happenings” at Stutthof because of her key administrative position, as well as the relatively compact layout of the camp.

A particularly gruesome practice carried out at Stutthof was the tricking of prisoners into believing their height was to be measured, when in fact SS men disguised as doctors would position them in order to shoot them in the neck from a viewing point in an adjoining room. This method was used to shoot around 30 prisoners within a two-hour timeframe. The bodies were subsequently hosed down, carted away and burnt.

Detainees were also forced into chambers filled from the rooftop with the poisonous gas Zyklon B. The court referenced witness accounts relating how those trapped inside screamed in agony, clawing at their skin and tearing out their own hair due to the pain.

The associated noises and smells pervaded the camp and, not least due to additional sights she would have witnessed and verbal communications, it would have been “unavoidable” for Furchner not to know what was occurring, the trial heard.

In a statement to the court, Molkentin said Furchner distanced herself from attempts within far-right circles to label her a hero and said that unlike some of her supporter she was “not a Holocaust denier”. But he said she resented being treated in the same light as high-ranking officials who were no longer alive to take the blame for the crimes committed.

“Irmgard Furchner does not deny the crimes of the Shoah [Holocaust],” Molkentin told the court as the defendant rubbed her temples and looked towards the ceiling. “Neither does she deny the terrible acts that took place as has once again been made clear to us all in the indictment. She simply rejects the charge around which this trial ultimately revolves, that she was personally guilty of a crime.”

Christoph Ruckel, a lawyer representing five co-plaintiffs from the US, France and Austria, who are due to give evidence over the coming months, asked the court to reconsider its rejection of his request to arrange a visit to the memorial site at Stutthof for the state prosecutor and lawyers. “This source of knowledge cannot really be replaced by other means of evidence,” he said.

“A visual inspection of the [site] by the trial participants would allow them to see that the defendant would have – both on her daily route to work and from her view from the building of the commander, where she had her office … had to observe the existence of a gas chamber, a crematorium, a gallows and the omnipresent daily inhumane treatment of the detainees … both acoustically and visually.”

Speaking outside the courtroom, he urged the court to recognise the importance of ensuring the trial was completed. “Those I am representing here are just as old as Irmgard Furchner,” he said. “They need closure. As one of them, who has since died, wrote to me: ‘I haven’t come to the finishing line yet.'”

The trial is being filmed for historical purposes. The judge, Dominik Gross, underlined the importance of the unusual step to allow the recording, calling it “one of the worldwide last criminal trials related to crimes of the Nazi era”.

Furchner is the first woman to go on trial for Nazi-related crimes in decades. Another trial of a 100-year-old former concentration camp guard is taking place in Brandenburg.

The prosecution case against Furchner is being brought as a result of the trial of John Demjanjuk, a former camp guard at Sobibor concentration camp, who in 2011 was convicted of aiding and abetting the murders of 28,000 people, setting a new legal precedent.

It is scheduled to continue over the next few months. Sessions are limited to about two hours a day, based on medical advice.