Obama, 26, the youngest of the presidential candidate's half-brothers, spoke for the first time about his life to the Italian edition of Vanity Fair.
Barack and George are both born of the same father, Barack Hussein Obama, but to a different mother, named only as Jael.
"No-one knows who I am," he told the magazine, before claiming: "I live here on less than a dollar a month."
Embarrassed by his living conditions, he said that he does not mention his famous half-brother in conversation.
"If anyone says something about my surname, I say we are not related. I am ashamed," he said.
Obama in his acceptance speech in Denver says, "I am my brother's keeper." However, he hasn't offered to help his own brother.
Barack mentions his brother in his memoir, "Dreams for my Father," in just one passing paragraph as a "beautiful boy with a rounded head."
The Democratic presidential candidate also described the moment he met George and the rest of his family he had never known, as a "painful affair."
Of their second meeting, George Obama said: "It was very brief; we spoke for just a few minutes. It was like meeting a complete stranger."
Dinesh D'Souza, author and blogger, started a fund for the George and it's called the "George Obama Compassion Fund" which has the goal of raising money to help George move out of his one-room hut. He has so far he's raised $2,000, mostly from very modest contributions.