George Obama was charged with possession of cannabis in his home in a Nairobi suburb, and is due to appear in court today.
The head of police said: “He is not a drug dealer. But it is illegal, it is a forbidden substance.”
George (26) spoke to CNN from the Huruma prison in the capital: "They took me from my home. I don't know why they are charging me."
Possession of marijuana in Kenya is usually tolerated, despite being illegal.
George Obama is the youngest of Barack Obama Senior’s eight children and was only sixth months old when his father died in a car crash. George hardly knows his half-brother, US President Barack.
Even new President Barrack Obama admitted to taking drugs in his autobiography: “I partied a lot, drank a lot and took drugs. Cocaine and Marijuana."