Inspector Augustine Mutembei, the officer in charge, said George Obama was arrested on charges of possession of cannabis, known in Kenya as Bhang, and resisting arrest. Is scheduled to appear in court on Monday Mutembei said.Being held in Huruma police post in the capital Nairobi.
Speaking from behind bars, Obama denied the allegations.
"They took me from my house," he said, "I do not know why I am being charged."
Obama and President George barely know each other, although they have met. George Obama is one of the few close relatives of the president was not to the inauguration in Washington last week.
In his memoir, "Dreams from My Father," Barack Obama describes meeting George as a "painful affair." Barack Obama's journey to Kenya means family reunion had never known.
George Obama in August found at small house in Huruma, a slum in Nairobi, where he lives with his mother's extended family. His birth certificate shows that Barack Obama is the half brother.
The two men share a father from Kenya. In the report, Barack Obama struggle to reconcile with her father after she left him and his mother when he was just a child.
Mr. Barack Obama died in a car accident when George was only 6 months old. Like his half brother, George hardly knew his father.
His father George was the last child and had not been aware of his famous half-brother growth.
Unlike his grandmother in Kogel in western Kenya, George Obama has received little attention from the media reports about it until it appeared in August.
The reports came from an Italian Vanity Fair article saying George Obama lives in a shack and "earning less than a dollar a day." Those reports left George Obama angry.
"I was well educated. I live well even now," he said. "The magazines, which have exaggerated everything.
"I think I like it here. There are some challenges, but maybe it's like where you come from, are the same challenges," said Obama.
Obama, who is in his mid-20s, said at the time he was learning to be a mechanic and is active in youth groups in Huruma. He said he tried to help the community as much as possible.