An immigration tribunal found the 27-year-old was guilty of crimes against humanity after interviews given to the BBC and The Times described his looting of 30 villages and the shooting of "countless" victims.
The man was a member of the feared Janjaweed militia, which killed as many as 300,000 people in Sudan and displaced up to two-and-a-half million others.
Immigration officials said that he was exempt from refugee status under the Geneva Convention, which allows the refusal of asylum for war criminals, but a judge overruled them, arguing the man's life would be at risk if he was deported and that his human rights to life and protection against torture would be infringed if he went home.
The man, wrapped in black scraf to cover his face, said in the 2008 Newsnight interview: "You will not distinguish between children, the elderly or women. You just shoot and kill everybody."
The interviews were also damning about his former commanders and and revealed embarrassing political information about the genocide, and it is believed his identity is known to the Sudanese community in Britain, who might relay the information to relatives at home if he returned.
Judge CJ Lloyd said in October last year she thought it was "fairer" to examine the evidence he gave to the tribunal, rather than in the interviews, where he said he had "never killed anyone in his life but was careful to shoot in the air."
These grounds for asylum were overturned by a second judge, but he upheld the separate human rights ruling which found the man would be at risk of his life in Sudan because his identity would be known from his BBC appearance.
The man will not be able to work, study or claim benefits in Britain, but has the right to remain indefinitely.
