The father of runaway aristocrat Constance Marten has spoken of his relief that she has been found but added it would have been “far better if they had handed themselves in earlier”.

Napier Marten, who has issued two heartfelt pleas for her return, told The Independent that “whatever the weather, I love her dearly and will support her best I can”.

But he added that he was extremely worried about her newborn child who has not been found and is the subject of a huge search by police.

Constance and her partner Mark Gordon are in police custody after being arrested in Brighton on suspicion of child neglect, officers have confirmed. The couple’s newborn baby was not found.

Metropolitan Police said an urgent search operation is underway to find their baby who has not received medical attention, as DSI Lewis Bashford revealed that the couple have not told them, where the baby is or even its gender.

Speaking exclusively to The Independent, Mr Marten said: “It would have been far better if they handed themselves in earlier and whatever the weather, I love her dearly”.

He continued by saying it is “very alarming” that the couple’s newborn baby is missing.

“It is an immense relief to know my beloved daughter Constance has been found, tempered by the very alarming news her baby has yet to be found”, he said.

“For whatever reasons she and her partner went on the run, the consequences of their actions have increased many fold. It would have been far better if they had handed themselves in earlier.”

He continued: “The police to whom I am profoundly grateful, committed great resources to try to find Constance, all of which, it was always hoped, could have been avoided.

“I would like to thank Det. Sup. Bashford and his team for their dogged investigation to bring her disappearance to a close. I would also like to thank the person or persons who called the Police when they saw the couple.

“When the time comes, I am longing to see Constance to reassure her that, whatever the weather, I love her dearly and will support her as best I can through the difficult weeks and months here on in.”

Ms Marten, 35, and Gordon, 48, have been travelling around the UK by taxi since their car was found burning on the M61 in Bolton, Greater Manchester, on 5 January.

Shortly after the couple disappeared in early January with their baby it transpired that Gordon was jailed in the late 1980s in Florida, US, after raping and assaulting a woman when he was 14.