Guangzhou, China (CNN) -- In a new book, the half brother of President Obama claims the father they shared was often drunk and physically abusive.
"My father beat me," Mark Obama Ndesandjo told reporters in China, where he lives. "He beat my mother. You just do not do that. I shut these thoughts in the back of my mind for many years."
Ndesandjo, who took the last name of the man his mother remarried, has dodged the media in the year since his half brother was elected U.S. president. However, he spoke out Wednesday regarding his semi-autobiographical book, "Nairobi to Shenzhen."
An engineer by trade, Ndesandjo moved to Shenzhen, China, after losing his job in the United States seven years ago. He owns a small chain of restaurants in Shenzhen and teaches piano to orphans.
He said that he struggled with the name Obama for years, telling few about his family.
But he said something happened to change that after he watched Obama's victory celebration in Chicago, Illinois' Grant Park following the 2008 election. His own despair turned into hope, he said.
"I saw millions of people who loved or supported my brother Barack, and in the process, in some weird way, I came to terms with many things that I had shut out of my life, including the Obama name," he said.
In his book, "Dreams of My Father: A Story of Race and Inheritance," Obama writes that he grew up in Hawaii, raised by his mother and her parents, after his father, Barack Obama Sr., returned to Africa. He recalls a monthlong visit with his father when he was 10 and going to Kenya after the elder Obama's death. In the book, Obama acknowledges his father was an alcoholic.
There was no immediate reaction from the White House to Ndesandjo's comments.
Ndesandjo said he has met with Obama infrequently over the years but said he would like to introduce his half brother to his Chinese wife when Obama makes his first official visit to China this month.
Presidential brothers, such as Billy Carter and Roger Clinton Jr., historically have not had an easy ride. However, Ndesandjo said he wants to live his life and tell his own story, not have others tell it for him.
CNN's John Vause contributed to this report.