ARISTOCRAT Constance Marten and her lover have been further arrested on suspicion of gross negligence manslaughter as cops search for their baby.
At a press conference on Tuesday afternoon, police said there is a "possibility the baby has come to harm".
And they added the search "may not end as we like".
But police said they "remain hopeful" as they continue extensive searches across 91-square miles of East Sussex for the newborn.
A spokesperson for the Metropolitan Police said: "We feel the risk is getting so great that we now have to consider the possibility that the baby has come to harm."
The charge of gross negligence manslaughter gives police powers to detain the couple for a longer period of time while they are questioned.
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A Met Police spokesperson, speaking alongside Sussex Police, told The Sun cops still do not know the gender of the baby.
A former police detective told Sky News this may suggest Marten, 35, and boyfriend Mark Gordon, 48, are not answering questions in custody.
After 54 days on the run, the pair were finally arrested on Monday night in Stanmer Villas, Brighton - but their baby was nowhere to be seen.
A tearful Constance yelled at police to "get off" her lover Mark Gordon when he was restrained by cops, witnesses claim.
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The pair were last night held on suspicion of child neglect.
They left their home in Eltham, South East London, sometime in September 2022, and began a nomadic lifestyle.
Before they vanished, it is thought Marten withdrew £15,000 of cash from an ATM.
The couple's car was found on fire on January 5 on the M61 near Bolton, Lancashire - it is thought Constance gave birth in or near the vehicle in the days surrounding the incident.
It comes as...
- Missing aristocrat Constance Marten & lover Mark Gordon arrested but baby STILL missing
- Mystery over gender of baby as cops test placenta found in car
- Dramatic moment ‘screams’ heard as Constance’s lover restrained on floor during double arrest
- Marten’s father Napier ‘relieved’ aristocrat has been found but ‘alarmed’ her baby is still missing
- Police find child’s ear muffs after searching bins in fingertip search of allotment
They were then spotted on CCTV at various locations across Liverpool, London, Essex and East Sussex hiding their faces with hoods and facemasks.
Arrested without their newborn on Monday - police have launched a desperate hunt searching under cars and behind bins in Stanmer Villas and nearby Roedale Valley Allotments.
The allotment is now being treated as a "potential crime scene".
Following the pair's disappearance, police told how the aristocrat became estranged from her family after meeting Gordon when she was a drama student in 2016.
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The daughter of Napier Martin, a former page to , and granddaughter of Mary Anna Marten, whose godmother was the Queen Mother, Constance comes from a family of wealthy landowners.
She was deemed an 'it girl' when she appeared on upmarket mag Tatler's babe of the month page while she was a student in 2008.