German prosecutors have confirmed they are investigating a 93-year-old woman on suspicion that she served as a Nazi SS guard during World War II, after she appeared in an RTÉ documentary last year.

Hilde Michnia is suspected of forcing prisoners on an evacuation march in 1945 during which about 1,400 women died.

Hamburg prosecutors' began investigating her last week after a social worker filed charges against her.

Hans-Jürgen Brennecke filed the charges after seeing the RTÉ documentary 'Close to Evil' in which Bergen Belsen survivor Tomi Reichental attempted to interview Michnia.

In the documentary, Michnia admitted to taking part in the evacuation.

"She said herself, three times, 'I was on the death march.' I thought, hang on, there have to be some consequences if such important information is in (the film)," Mr Brennecke told UK newspaper The Guardian. "When I realised that no one had done anything yet, I thought: this can't be.

"It bothers me that so much is still kept silent, or misrepresented. I just want the facts to come out. Everyone is allowed to have opinions, but we need to know the facts. We're still not finished with it," Mr Brennecke said.

Last weekend, however, Michnia told a German newspaper she had not been involved in any atrocities and only worked in the kitchens.

"I didn't see any of it," she told Die Welt. "That was all in a completely different part of the camp."

Michnia was previously convicted for her work as a concentration camp guard in 1945.

Mr Reichental was named Ireland's International Person of the Year at an awards ceremony in Dublin in December.

It was in recognition of his work educating young people about the Holocaust.

A number of cases are currently being taken in Germany against alleged SS guards.

Today it was also announced a 93-year-old former Auschwitz death camp officer would go on trial in Germany in April charged with at least 300,000 counts of accessory to murder.

Oskar Groening, known as the "bookkeeper of Auschwitz", will face charges over the 425,000 people believed to have been deported to the camp in occupied Poland between May and July 1944, at least 300,000 of whom were killed in the gas chambers.

Fifty-five co-plaintiffs, mainly survivors and victims' relatives, will be represented at the trial.