STANDING frail and aged at her doorstep it is difficult to believe that Erna Wallisch is ranked seventh on the blacklist of most wanted Nazi war criminals.

The Austrian Justice Ministry has vowed to reopen the case against the 85-year-old grandmother after she was uncovered living in a flat in Vienna, Austria, by Wiltshire author and historian Guy Walters.

Mr Walters, 36, of Heytesbury, near Warminster, visited her home last week as part of research for his forthcoming book Hunting Evil, which focuses on Nazi war criminals that have escaped prosecution.

The local author wasn't exactly made welcome when he introduced himself to Wallisch at her doorstep last Wednesday.

He said: "I told her I am a British writer and wanted to talk to her about her time in the war and she sort of scowled and shut the door very quickly but I managed to get a picture of her as she did.

"She used to beat up women and children as they were escorted to the gas chambers. She admits she was responsible but she said she was acting under orders and that it is all in the past.

"I dispute the fact it is in the past because thousands of others are dead but she still lives and she can still be brought to justice."

Born Erna Pfannenstiel, the daughter of a postal clerk joined the Nazi party at the age of 19 and served as a guard in Ravensbruck concentration camp in Germany from 1941 before transferring to the Majdanek camp in Poland a year later.

It is estimated that 130,000 women and children went through Ravensbruck camp during the war, of those only 40,000 survived.

The director of the Simon Wiesenthal Centre, which is named after a holocaust survivor who dedicated his life to hunting Nazi war criminals, spoke to Mr Walters on Tuesday exclaiming his excitement over news that she had been exposed.

The centre has blacklisted Wallisch as the seventh most-wanted Nazi war criminal still at large.

The centre is now demanding that action be taken by the Austrian Justice Ministry after she admitted her participation in the mass murder of inmates at the concentration camp in Poland.

Wallisch was married in 1944 to Nazi guard Georg Wallisch and even while pregnant she is alleged to have beaten inmates and chosen others for the gas chamber.

Now living alone, Wallisch rarely ventures out from her home, relying on others to bring her groceries. Hunting Evil is due to be released in 2009.