A 100-year-old man has gone on trial in Germany, accused of being an accessory to murder for serving as a Nazi SS guard at the Sachsenhausen concentration camp near Berlin during the Second World War.

The trial of the defendant, who is charged with 3,518 counts of accessory to murder, was held at the Neuruppin state court, which moved the proceedings to a prison sports hall in Brandenburg for organisational reasons.

The suspect, who was identified only as Josef S in keeping with German privacy rules, is alleged to have worked at Sachsenhausen between 1942 and 1945 as an enlisted member of the Nazi Party's paramilitary wing.

The suspect's lawyer, Stefan Waterkamp, told the court that his client did not want to comment on the allegations, German news agency dpa reported.

There are no formal pleas in the German legal system.

Authorities say that the defendant is considered fit enough to stand trial despite his advanced age, though the number of hours per day the court is in session will be limited.

More than 200,000 people were held at Sachsenhausen between 1936 and 1945.

Tens of thousands of inmates died of starvation, disease, forced labour and other causes, as well as through medical experiments and systematic SS extermination operations including shootings, hangings and gassing.

Exact numbers on those killed vary, with upper estimates of some 100,000, though scholars suggest figures of 40,000 to 50,000 are likely to be more accurate.

"The defendant knowingly and willingly aided and abetted this at least by conscientiously performing guard duty, which was seamlessly integrated into the killing system," prosecutor Cyrill Klement told the court.

A survivor of Sachsenhausen, 100-year-old Leon Schwarzbaum, attended the trial as a visitor.

"This is the last trial for my friends, acquaintances and my loved ones, who were murdered, in which the last guilty person can still be sentenced - hopefully," Mr Schwarzbaum, who also survived the Auschwitz death camp and Buchenwald concentration camp, told dpa.

The opening of the trial comes a week after the opening of another elderly concentration camp suspect's trial was disrupted.

A 96-year-old former secretary for the Stutthof camp's SS commander skipped the opening of her trial at the Itzehoe state court in northern Germany.

She was tracked down within hours and proceedings are to resume on October 19.