An Afghan boy found alone at Heathrow should go into council care in England, a High Court judge has decided.
The youngster, thought to be about 12, had been discovered unaccompanied at the airport and temporarily placed with a foster carer by council social services staff, Mrs Justice Theis had been told.
He said his trip had been "planned and paid for" by his mother, who thought he would have a "better and safer" life in Britain.
Detail of the case has emerged in a ruling by Mrs Justice Theis following a family court hearing in London.
Social services bosses at Hillingdon Council had asked her to make decisions about the boy's future.
She said the boy could not be named.
"There is some uncertainty as to precisely how he arrived at Heathrow Airport, and what methods of transport he had between Afghanistan and the United Kingdom," said the judge.
"The whereabouts of his mother are unknown and it would be impossible to return (him) to her care in Afghanistan at this time."
She said it was right that a council bosses should be able to exercise parental responsibility.
The judge said she had been asked to decide how the boy's welfare interests could best be met.
She said Home Office officials would make decisions about his immigration status.