A boy whose father murdered his mother should live with his paternal relatives in England - not his maternal family in China, a family court judge has ruled.
Mr Justice Holman said the boy was a British citizen and grew up in England. He said a move to China would involve "huge upheaval".
Detail of the case has emerged in a written ruling on the case following a hearing in a family court in Birmingham.
The judge said the boy - now six - could not be named.
Mr Justice Holman said the boy's father brutally murdered his mother in a "very premeditated and carefully planned attack" and was serving a life sentence.
The judge said the boy was placed with foster parents following the killing.
He said social services staff asked him to make decisions about the boy's long-term future.
The boy's mother was Chinese and his father a British citizen of Chinese ethnicity.
He said the boy could not remain a foster child and said the options were a move to a couple related to his father in England or a move to his maternal grandparents in China.
"Within the space of a few days (the boy) effectively lost both his parents," said Mr Justice Holman in his ruling.
"His mother was dead. His father was incarcerated, and (the boy) has not seen him since."
The judge added: "As soon as his father was arrested, (the boy) was placed with sensitive and caring foster parents who continue to care for him with devotion and skill.
"But he should not remain a foster child. The issue I have to decide is whether he should now move to live permanently with his maternal grandparents, who live in a city in China, or with his father's (relatives)."
Mr Justice Holman said a move to paternal relatives in England was "clearly" in the boy's overall best interests.
"The strength of the case of the grandparents is that they are indeed his closest living maternal relatives and a last living link to his mother," said the judge.
"That does not, in my view, outweigh the huge upheaval that it would involve for him now to move to live in China."
He said the boy had suffered "an immense emotional and psychological shock already" and a move to a new home needed to be "as smooth and uncomplicated" as possible.
"The issue of great concern in relation to the (father's relatives) is their relationship to the perpetrator father. In many cases, this might rule them out," said the judge.
"I am quite satisfied that this particular aunt and uncle have completely satisfied themselves of the father's guilt. They do not in any way whatsoever attribute responsibility to the mother.
"They will not give to (the boy) a skewed version of events as he grows up, and indeed they are better placed than the grandparents in this case to enable (the boy) to grow up with a fair, true and proper understanding of his tragic history.
"In all other respects, a move to (the father's relatives) can only be very positive for (the boy).
"He knows them and their children well. He has a considerable attachment to them already. There are no reservations about their parenting capacities or material security. They have arranged, and can provide, a relatively seamless move to a school not markedly dissimilar to his present one."