The question remains obscure. Hitler's grandmother's Jewish employers did treat her pregnancy in a way that pretty much fits with what a wealthy family would do if the young buck got the maid pregnant. Then too, the SS or whoever did investigate the matter at Hitler's request -- and the results were suppressed. Finally, after the annexation of Austria, Hitler arranged for the entire village and surrounding area in question to be requisitioned for an artillery firing range and razed... All very suggestive. I'd say Hitler himself must have had his doubts. Offhand, I'd say neither he nor we will ever know for sure. Actually, given that there are surviving relatives, some of the more new-fangled DNA tests might shed some light, although since Jewish bloodlines are good deal more intermingled with everyone else's than either Jews or those who hate them like to admit, I'm not sure the results could be more than suggestive.
Wreckage found on Reunion island triggers speculation over missing MH370 (DPA)
from the article: Is Ahmadinejad trying to hide his Jewish roots by bashing Israel?