Mark Obama Ndesandjo, who has written a memoir about his father, said their father was a "social failure" and an abusive husband, CNN reported Friday.
"I remember the sounds of my mother's screams and I remember the sounds of breaking, things breaking," Ndesandjo told CNN. "And I remember that I couldn't protect her. That's something that no child ever forgets."
Barack Obama apparently met their father only once because his parents had divorced soon after he was born. While they share the same father, Obama's mother was the second wife while Ndesandjo's mother was his third wife.
The president was fortunate he never lived with his father, said David Maraniss, author of "Barack Obama: The Story."
"It would have been a much more difficult upbringing," he said.
Differing remembrances of family history have caused some tension among Obama relatives, Ndesandjo told CNN.
"Barack I don't think accepts -- or at least does not want to know -- the details of the beatings that occurred in our family," he said. "I love my brother. He's a great president. Sometimes he's a lousy brother."
The White House did not respond to emails and phone calls Thursday about the president's half-brother's book. But in a 2009 interview with CNN, the president said he was aware of his father's flaws.
"It's no secret that my father was a troubled person. Anybody who has read my first book, 'Dreams from My Father,' knows that, you know, he had an alcoholism problem, that he didn't treat his families very well," Obama said in the 2009 interview. "Obviously it's a sad part of my history and my background. But it's not something that I spend a lot of time brooding over."
Ndesandjo, who lives near Hong Kong, said he hopes his book, which will be published in February, helps to raise awareness of domestic violence. He said some of the proceeds will go to his foundation for disadvantaged children.