A former Nazi concentration camp guard said at his trial Tuesday that he was ashamed at having been part of the SS and that he was unaware of the systematic killings there. Johann Rehbogen is accused of complicity in mass murder at the Stutthof camp near what was then Danzig, now Gdansk in Poland. Dressed in a dark grey suit, the white-haired 94-year-old was wheeled into the German court, holding a walking stick in his right hand. In rare testimony in one of the last cases of its kind, Rehbogen said in a statement read out by his lawyer that he was forced into service and denied having ever been a Nazi. "I'm of course ashamed to have been part of the SS. But I still don't know today if I would have had the courage to do otherwise," he said. He said he was forced into joining the Schutzstaffel troops as he feared "reprisals against my family if I hadn't gone". "When I saw the detainees I knew that the SS was wrong but I didn't have a choice to do otherwise," said Rehbogen, who served as a guard from June 1942 to September 1944 at Stutthof. He denied knowledge of the gruesome crimes at the camp, insisting: "I knew nothing of the systematic killings, I knew nothing of the gas chambers as well as the crematoria." Rehbogen said he "would have liked to leave" the camp but added that "I did not trust myself to speak with anyone and had no one I could trust". "I will only say that I am not a Nazi, I never have been one, and never will be." - 'I don't believe him' - But lead prosecutor Andreas Brendel said that there were "ways out" of serving at the camp for guards like Rehbogen. "We believe that the guards knew a lot more than what has been recounted today," he said. Plaintiffs voiced dismay at Rehbogen's statement. "I am disappointed but not surprised to hear the defendant is denying that he took part in the killings at Stutthof," said Benjamin Cohen, who represented his grandmother Judy Meisel at the hearing. "My grandmother's account of her time in the camp and the murder of her mother tells a very clear story about the role of these guards." Manuel Mayer, a lawyer of a former detainee, said: "His statement was absurd. I don't believe him." Rehbogen is due to reply to plaintiffs' questions when the trial resumes on Thursday. Rehbogen was aged 18 to 20 at the time and is therefore being tried under juvenile law. He is charged with being an accessory to the murders of several hundred camp prisoners. These included more than 100 Polish prisoners gassed in June 1944 and "probably several hundred" Jews killed from August to December 1944 as part of the Nazis' so-called "Final Solution". If found guilty, he faces a sentence of up to 15 years in prison. Given his age and the possibility of an appeal he is considered unlikely to serve any time behind bars. Rehbogen, from North Rhine-Westphalia state, is a retired landscape architect and divorced father of three, according to German media. At the trial opening last week, he shed tears when he heard written testimony from Holocaust survivors. - 'Symbolic but important' - Christoph Ruecken, a lawyer representing an 85-year-old Holocaust survivor who now lives in the United States, said: "A punishment would be symbolic for such an old man but that's important in times like now when nationalism and anti-Semitism are returning. "It's important to show that the rule of law says you will face the court if you do these things." Stutthof was set up in 1939 and ended up holding 110,000 detainees, 65,000 of whom perished, according to the Museum Stutthof. Germany has been racing to put on trial surviving SS personnel, after the legal basis for prosecuting former Nazis changed in 2011 with the landmark conviction of former guard John Demjanjuk. He was sentenced on the grounds that he served as a cog in the Nazi killing machine at the Sobibor camp in occupied Poland, rather than for killings or atrocities linked to him personally. German courts subsequently convicted Oskar Groening, an accountant at Auschwitz, and Reinhold Hanning, a former SS guard at the same camp, for complicity in mass murder. Both men were convicted at age 94 but died before they could be imprisoned.