The newborn missing along with parents Constance Marten and Mark Gordon may have been dead “for some time,” police admitted today.
Aristocrat Ms Marten, 35, and her partner Mark Gordon, 48, remain in custody and will also be questioned this morning.
Their arrest on Monday in Brighton ended a nationwide police hunt that began when they fled seven weeks ago with their newborn baby. Police detained them on charges of child neglect and then on suspicion of manslaughter by gross negligence, but they have refused to speak to officers about their child being born in secret.
Detective Superintendent Lewis Basford said the case has been referred to the police watchdog.
He added: “At this stage we have not been able to confirm the sex of the baby and an autopsy has not yet taken place.
“Despite this, based on our investigations we have conducted to date, we unfortunately believe that the baby had been dead for some time before they were found.
“It is still too early for us to give a more specific date.
Police officers hang crime scene tape on a number of allotments, north of Shenfield Way, near the crime scene in Brighton, East Sussex, where remains were found when searching for Constance Marten and Mark Gordon’s two-month-old baby

Police at the allotments are thoroughly searching the area today as they investigate the death
A source told The sun they had frequented the J & E Fish Bar in the weeks before – and they only frequented the parade of shops in Hollingbury Place at night, always without the baby.
Police had long theorized that the pair may have evaded authorities by camping in a tent or hiding in a shed.
Officers were seen putting up blue screens at allotments in the resort town with a frenzy of activity on the grounds.
A woman told MailOnline: ‘Police arrived at 4.45pm yesterday and asked if they could use my garden to access the woods behind.
“They were carrying screens and equipment. They went to a place behind the allotments about 100 meters away.
“I couldn’t see what they were doing, but there were quite a few of them.
“The officers later carried away boxes, which we believe contained material they considered important to their investigation.”

Mark Gordon, 48, and Constance Marten, 35, had been missing for 54 days and slept rough in a tent
Another resident added: “The officers told us as a courtesy that they found the baby’s body there.
The body was found in the woods. I don’t know if the body is buried. But it’s tragic to think that that little kid was left there, so close to where we live.’
An autopsy is expected today to determine how and when the child died.
Police had long feared for the child’s chances of survival due to a lack of medical care and sub-zero temperatures and these worst fears became a reality yesterday
Speculation arose yesterday that the death could have been days or weeks ago, as the couple was spotted several times without the child.
They were seen on CCTV on Feb. 11 entering a fish and chip shop in Brighton, shopping at a convenience store and later visiting food banks, according to locals.
The last person to see the child alive was on January 7 when the pair took a taxi in Whitechapel, east London.

Sussex Police Chief Inspector Lewis Basford (R) and Police Chief James Collis (L) reveal last night that the baby they were looking for has been found dead
Authorities were unaware of the birth until the couple’s car suffered an electrical fault and caught fire on the M61 near Bolton on 5 January, destroying all their belongings.
The couple left the wreckage and crossed the country with the baby, who was barely a day old at the time, as police became increasingly concerned that the child had not received medical attention.
They traveled by taxi, paid for everything in cash, covered their faces while on CCTV, and were often on the road, often in the dark.
On Monday evening, the police finally tracked down the couple in Brighton after a tip-off.
A member of the public clocked them off at the corner ATM and followed them back to their hideout. The use of the ATM also caused an alarm with the alerted police.
Yesterday, a businessman, who declined to be named, said: “They were captured on CCTV in the area as early as February 11.
‘They have been seen going into the chippy and the Mulberrys (shop) and only going out at night.
“Gordon has a leg injury and used the tree branch as a walking stick. They were never seen with the baby, or pushing a stroller or anything like that. It’s heartbreaking to think what could have happened to that poor baby.’
Days before her arrest, Marten, who comes from a wealthy family with ties to the royal family, visited Brighton’s food bank.
One worker said they didn’t charge for a baby, even though they had plenty of diapers and baby food, adding: ‘They were given canned food, bread, pasta, milk and rice. They were not registered with us, as we usually do.

: Aristocrat Constance Marten, 35, who went missing with her lover Mark Gordon, 48

A police search team searches an area of woodland near where the baby was found

This is runaway aristocrat Constance Marten (right) and her lover Mark Gordon (left) just before their arrest in Brighton on Monday. Audio from them passing by this house revealed that they may have been rowing
“The baby wasn’t with them. We have supplies here, but they didn’t charge for a baby. But they themselves came to ask for help.
‘She did the talking and the man was left with his hood up. She asked for help. She wore many layers and looked like she had been out for a while.
He checked the area. He stepped back and wouldn’t make eye contact. She spoke. We didn’t take any details, we just fed them because we thought they needed help.’
Over the past 48 hours, more than 200 police officers and search and rescue experts have scoured 90 square miles of rural Sussex looking for the child using helicopters, sniffer dogs, thermal imaging cameras and drones.
Superintendent Lewis Basford, who is leading the investigation for Sussex Police, said last night: “It is my very sad duty to report that this afternoon police officers searching an area of woodland near where Constance Marten and Mark Gordon were arrested found the remains of a baby. There will be a post-mortem examination in due course.
“A crime scene is present and work on the site is expected to take some time. This is a result that I and the many agents who took part in the search had hoped would not happen.” Last night, the pair remained in custody after magistrates granted a request to extend their detention for a further 36 hours.
Inquiries revealed that Marten had given birth in the back of the car before it caught fire and had not been assessed by medical professionals.
She was apparently in tears during the arrest and yelled at officers to get rid of her lover when he was detained because she was concerned about his mental health.
A bystander claimed he struggled and took 40 minutes to be overcome. Another said he was “very angry” and yelling. A search dog van was seen driving onto the road leading to allotments which were the focus of the police search.
Marked police vehicles were stationed along the route and a uniformed officer stood guard at the bottom of the road.
Set in a 240-acre nature reserve, the woodland is on the direct off-road footpath between Newhaven and Fiveways, the Brighton area where the pair were arrested on Monday night.
Marten and Gordon were initially detained on suspicion of child neglect, before being re-arrested the following day on suspicion of grossly negligent homicide.