Police have applied for an extra 36 hours to question Constance Marten and Mark Gordon as a major search for their missing baby continues near Brighton.
Officers said it was possible the baby may have “come to harm” as London Search and Rescue (LONSAR) officers continued to search Wild Park Local Nature Reserve, near Moulsecoomb, on Wednesday.
The officers, some wearing jackets indicating they were dog handlers, searched underneath sticks and logs close to where the area meets Hollingbury Golf Course.
The couple have not provided police with any details about their baby’s location after they were arrested on suspicion of gross negligence manslaughter following 54 days on the run.
The pair remain in police custody in Sussex after a member of the public spotted them near a shop in Brighton on Monday evening.
In a brief update to reporters, Met Detective Superintendent Lewis Basford said: “This is a hugely difficult and painstaking search operation, covering a vast area of some 90 square miles.
“We’re using every resource we have at our disposal to find the baby.”
He urged the public to remain vigilant and continue providing information to the investigation team.
The couple had been missing since January 5 when their car was found on fire, abandoned on the M61 in Bolton, shortly after police believe Marten had given birth in or near the vehicle. More than 200 officers from Metropolitan and Sussex police are continuing the search operation for the baby.
Thermal imaging cameras, drones, sniffer dogs and the police helicopter are being used to scour the Sussex countryside between Brighton and Newhaven.
A heavy police presence remains near Stanmer Villas, where the couple were arrested. A search dogs van was seen near the Roedale Valley Allotments, which was thoroughly searched by officers on Tuesday.
Police are urging anyone between Newhaven and Brighton to report any suspicious behaviour or items found in their gardens, outbuildings and sheds between January 8 and now.
Detective Superintendent Lewis Basford said: “If you are out walking in these areas and you discover something you think we should know about, please don’t hesitate to contact us, no matter how insignificant it may seem. Support from the public is vital and we ask people to remain vigilant.”
A member of the public, who had seen media reports about the couple, phoned 999 on Monday shortly before 9.30pm after seeing them withdraw cash from a convenience store in Hollingbury Place.
Officers arrived six minutes later, with Marten, 35, and Gordon, 48, being detained at nearby Stanmer Villas and arrested on suspicion of child neglect.
Since then, hundreds of officers have been searching an area of seven miles by 13 miles for the baby, from where the couple were last sighted to where they were arrested – including allotments and woodland.
Detective Superintendent Basford said police still hoped to find the child safe and well, but he said police had to consider the possibility the baby had “come to harm”.
He said officers had received no information about the welfare or location of the child since the pair were detained.
“We have had a significant period of time in the custody facility with both Constance and Mark,” he said.
“At this time we have not furthered that information, which has now obviously led to the position where we feel that the risk is getting so great that we now have to consider the possibility that the baby has come to harm.”
He conceded the cold weather meant that officers had to be open to the investigation not “ending in the way we would like”.
Inquiries revealed Marten had given birth recently – possibly one or two days before their car was found on January 5 – and had not been assessed by medical professionals.
The pair had used taxis to first travel to Liverpool, then Harwich in Essex, and on to east London, before arriving in Sussex on January 8.
The couple avoided detection by only making payments in cash, hiding their faces on CCTV and often moving around at night or in the early hours of the morning.
CCTV images show the pair buying camping gear in east London, and police believe they slept in a tent in sub-zero temperatures.
Mr Basford said police are yet to locate items bought by Marten and Gordon at Argos on January 7, adding: “We would still say we are actively looking for those.”
Marten’s father said it was a huge relief that his daughter had been found but it was “very alarming” that her baby remains missing.
Napier Marten told the Independent he loves his daughter but it would have been “far better” if she and Gordon had handed themselves in earlier.
“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,” he said.
Marten, who is from a wealthy aristocratic family, was a promising drama student when she met Gordon in 2016.
Since then the couple have led an isolated life and, in September, as Marten’s pregnancy progressed, began moving around rental flats.
Gordon served 20 years in prison in the US for rape and battery committed when he was 14.
Anyone with any sightings or information that could assist the search is asked to call the incident room on 0208 3453 865 or 999 with anything they believe may be significant.
