Saliva samples taken from 39 relatives of the Nazi leader show he may have had biological links to the “subhuman” races that he tried to exterminate during the Holocaust.
Jean-Paul Mulders, a Belgian journalist, and Marc Vermeeren, a historian, tracked down the Fuhrer’s relatives, including an Austrian farmer who was his cousin, earlier this year.
A chromosome called Haplogroup E1b1b1 which showed up in their samples is rare in Western Europe and is most commonly found in the Berbers of Morocco, Algeria and Tunisia, as well as among Ashkenazi and Sephardic Jews.
"One can from this postulate that Hitler was related to people whom he despised," Mr Mulders wrote in the Belgian magazine, Knack.
Haplogroup E1b1b1, which accounts for approximately 18 to 20 per cent of Ashkenazi and 8.6 per cent to 30 per cent of Sephardic Y-chromosomes, appears to be one of the major founding lineages of the Jewish population.
Knack, which published the findings, says the DNA was tested under stringent laboratory conditions.
"This is a surprising result," said Ronny Decorte, a genetic specialist at the Catholic University of Leuven.
"The affair is fascinating if one compares it with the conception of the world of the Nazis, in which race and blood was central.
“Hitler's concern over his descent was not unjustified. He was apparently not "pure" or ‘Ayran’.”
It is not the first time that historians have suggested Hitler had Jewish ancestry.
His father, Alois, is thought to have been the illegitimate offspring of a maid called Maria Schickelgruber and a 19-year-old Jewish man called Frankenberger.