An estranged lesbian couple are embroiled in a Supreme Court fight over a seven-year-old girl born following IVF treatment.
Five Supreme Court justices are due to begin analysing evidence at a hearing in London following rulings by judges in the High Court and Court of Appeal.
One woman is the youngster's biological mother and sole legal parent while the second woman considers herself a "de facto" parent, courts have heard.
Their relationship broke down in 2011 - more than three years after the girl was conceived by IVF treatment and born.
Judges have been told the girl was taken to Pakistan by her biological mother in early 2014.
The second woman had then begun legal action and asked judges to order the youngster's return to the UK.
But High Court and Court of Appeal judges concluded they did not have the "jurisdiction" to make such an order because the girl was not habitually resident in the UK when legal proceedings were launched.
The second woman is now hoping that the Supreme Court will rule in her favour.
Supreme Court justices are expected to finish hearing evidence on Wednesday, but a ruling is not likely until next year.
No-one involved has been identified.
Mrs Justice Hogg initially analysed the case at a hearing in the Family Division of the High Court in 2014 and dismissed an application by the second woman.
A panel of appeal judges - which included Sir James Munby, the head of the Family Division of the High Court - dismissed an appeal by the second woman after a hearing in the Court of Appeal earlier this year.