The father of Constance Marten has said he is alarmed her baby is still missing as an urgent police search for the newborn continues.
Ms Marten, an aristocrat, had been missing along with her partner, Mark Gordon, and their baby since January.
The couple were found by police in Stanmer Villas, Brighton, on Monday night after a member of the public reported seeing them shortly before 9.30pm.
They have been arrested on suspicion of child neglect.
Napier Marten told The Independent he loves his daughter dearly but it would have been “far better” if she and Mr Gordon had handed themselves in earlier.
Mr Marten said: “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.
“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 added: “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.”
An urgent search for the couple’s baby is under way, with police having deployed a helicopter, drones and police dogs. Police said they believe the child is still alive.
Ms Marten and Mr Gordon had been travelling around the country by taxi after their car was found burning on the M61 in Bolton, Greater Manchester, on 5 January.
It is believed that Ms Marten gave birth to the child either in or near the car only a day or two earlier.
Police had been concerned for the welfare of Ms Marten and her baby on the basis that it was believed neither mother or child had received medical attention since the birth.
The couple travelled from Bolton to Liverpool, then to Harwich in Essex, then to east London and then to Newhaven in Sussex, where they were seen near the ferry port on 8 January.
Officers’ enquiries established the baby was alive and with Ms Marten and Mr Gordon when they got a taxi to Newhaven.
Since September last year Ms Marten and Mr Gordon have been living in Airbnb listings around the country.
They are understood to have been in possession of a significant amount of cash that enabled them to live off-grid and evade the attention of the authorities.
Last month police revealed they believed the pair and their baby were sleeping in a tent in sub-zero temperatures after Mr Gordon was spotted in an Argos on Whitechapel Road on 7 January, where he bought a blue two-man tent, two sleeping bags and two pillows.