A historian has breathed new life into rumours that Adolf Hitler’s grandfather was Jewish.

Dr Leonard Sax claims to have found new evidence to suggest that the Fuhrer may not have been as gentile as he claimed, The Sun reports.

Claims about Hitler’s supposed Jewish ancestry were first put forward by his personal lawyer, Hans Frank.

Frank, allegedly, uncovered evidence in 1930 that the Hitler’s grandad lived in the same home where his grandmother worked when she gave birth out of wedlock.

His claims were published seven years after his death when he was executed for war crimes following a trial at Nuremberg in 1946.

But ever since they surfaced many have rubbished the supposed evidence Frank had uncovered.

One German author, Nikolaus von Preradovich, even claimed to have proved that there were no Jews in Graz, Austria, in 1836 when Hitler’s grandmother, Maria Anna Schicklgruber fell pregnant.

But Dr Sax claims to have found evidence in Austrian archives that there was a Jewish community in the Austrian town before 1850 and that Preradovich was a Nazi sympathiser, appalled at the idea Hitler had any Jewish blood.

Dr Sax told MailOnline: “I have been thinking about the fact that neo-Nazis are offended by the suggestion that Hitler had a Jewish grandfather, because they hate Jews.

“Jews are often offended by the suggestion that Hitler had a Jewish grandfather, because they hate Hitler.

“But now, as nearly a lifetime has passed since the end of the Third Reich, maybe we are free at last to ask — not what is offensive, or what is not offensive — but what is true?”

Maria Anna Schicklgruber was a poor peasant who lived in a rural area, in northwest Austria.

Little is known about her life until she reached the age of 42, when she gave birth to her son Alois while still unmarried.

She refused to reveal the identity of the father and so “illegitimate” was entered into the baptismal register.

She went on to marry Johann Georg Hiedler, who later went on to be officially accepted as Alois’ father and his birth certificate was changed.

It is unknown why it changed from Schicklgruber to Hitler and not Hiedler.

Hitler’s ancestry came into question when opponents spread rumours that his grandfather was Jewish.

In 1931, Hitler ordered the SS to investigate the rumours, who found no evidence he had Jewish links, although some suspect they covered them up.

Hitler then ordered genealogist Rudolf Koppensteiner to publish a detailed family tree of his ancestry in 1937, which showed that his ancestors were all Austrian Germans.

But still rumours swirl around the ancestry of the architect of the Holocaust to this very day.

This article was first published on The Sun and was reproduced with permission