- 1 update
A Cambridge University academic kept her seven-year-old son in the UK unlawfully and must return him to his father in Japan, a family court judge has ruled.
Judge Angela Finnerty said the woman should not have brought the youngster to England until a family court in Japan had resolved a dispute she was having with the her estranged husband - an academic in Japan.
Detail of the judge's decision has emerged in a written ruling following a hearing in the Family Division of the High Court in London.
No-one involved was identified.
The father had asked Judge Finnerty to order his son's return to Japan under the terms of international civil legislation relating to child abduction.
Judge Finnerty said the man and woman - who had worked at different universities in Japan - split in 2013 after marrying nine years ago.
They had reached an agreement about sharing care of their son after mediation in Japan.
The woman had then been offered a post at Cambridge and said she wanted to take the youngster with her. The man objected.
And she had flown to the UK with the boy before a court in Tokyo had ruled on the dispute.
"I am satisfied that (the boy) has been retained in the United Kingdom unlawfully in breach of the father's custody rights," said Judge Finnerty.
"I must order the return of (the boy) to Japan forthwith."
She added: "The mother should have waited until the Family Court in Tokyo had resolved these disputes."