Looking into the rumor that BHO is a son of Hitler, couldn't find anything to support it other than the custom of German naming. If, as is rumored, Hitler and Eva Braun survived WWII and had a child, that child could have been BHO's mother. If the child was named Anna or Jo Ann, both names would have been family names that came from Hitler's grandparents. Otherwise there doesn't seem to be any other evidence to support this theory.
However, there is some evidence to indicate that Obama was not related to Barack Hussein Obama, Sr. According to this theory, he was born to Stanley Ann Dunham in Kenya, who claimed that he was BHO Sr.'s son. However, this theory states that BHO was actually Indonesian and not African. His father was not his adopted father, Lolo Soetoro but Mohammad Subud, also an Indonesian. So if this theory is true, BHO would not be black but 1/2 Indonesian. He would have Kenyan status due to his birthplace but be Indonesian as well. He was reportedly given Indonesian citizenship due to his adoption by Soetoro.
This link lays out the theory and shows interesting comparison photos between BHO and Mohammad Subud.
http:// www. thenationalpatriot.com/2014/01/the-real-obama-an-indonesian-muslim-socialist-puppet/