The British couple at the heart of the internet adoption row have been ordered to appear in an American court accused of abducting the twins.
Judith and Alan Kilshaw were served with a writ from Californian couple Richard and Vickie Allen minutes after they finished recording an episode of the Oprah Winfrey chat show in the USA.
It is understood the writ orders the Kilshaws to appear in a court in Arkansas to answer charges that they abducted the twins and deceived officials in the US and Britain when they adopted six-month-old Belinda and Kimberley.
Mr Justice Kirkwood is due to preside over a progress hearing about the twins, held behind closed doors, at the High Court in Birmingham, at 10am.
It was earlier thought the couple, from Buckley, north Wales, would attend the hearing at Birmingham's Priory Courts complex but reports said they were still in the US and planned to appear on more TV shows.
At the first hearing last month, also in private, the judge ruled Belinda and Kimberley should remain in the care of Flintshire County Council "for the time being" after hearing arguments from legal teams for the authority and the Kilshaws.
The judge said the case involved legal complexities "since it is not just English law that I have to consider, but the position also in one, two or perhaps three states of the United States of America".
He added: "In human terms, there are obviously various conflicting interests and claims. It has become perfectly clear to me that in order to get the right solution, some calm, responsible research is needed.
"To provide further assistance to the court, I have arranged for the Official Solicitor ... to join in this case to help".
Mrs Kilshaw, 47, and her 45-year-old husband gave the court solemn undertakings not to discuss the case or any of the arrangements for the twins with anyone unconnected with the hearing.