Police searching for a missing aristocrat, her partner and their newborn baby believe the family have been sleeping in a tent in sub-zero temperatures.
Constance Marten and Mark Gordon along with their child disappeared after they left their abandoned car near junction four of the M61 near Bolton almost three weeks ago.
Officers say the couple went into an Argos on Whitechapel Road, East London on Saturday, January 7 to buy camping gear.
Gordon, 48, appeared to enter the store alone and bought two big bags full of items, including a blue two-man tent, two sleeping bags and two pillows, before leaving at 6.40pm.
The couple were last seen on Brick Lane towards Bethnal Green Road Metropolitan Police
The family were last seen walking along Brick Lane, towards Bethnal Green Road on foot after failing to flag down a black cab.
Officers believe the family could be living within homeless communities either in London or further afield, or camping in more rural or wooded areas.
The 35-year-old mum may have given birth in the back of a car which was later found burnt out in the greater Manchester area, with some reports suggesting that the placenta had been found by fire crews.
Concerns started to grow as neither Marten, nor the baby have seen a doctor.
The Metropolitan Police are calling on anyone with information to come forward due to the "dangerous, potentially life-threatening, conditions" following sub-zero temperatures across Britain in recent weeks.
The couple were seen getting out of a taxi on Whitechapel Road in East London Metropolitan Police
Marten, whose family formerly owned the £100million Crichel House estate set across 5,000 acres in Dorset and has links to the Royal Family, disappeared on January 5.
The following day, the pair got a taxi at 3:30am and on January 7 they travelled 267 miles south to the port of Harwich.
They were then spotted in Colchester, Essex at 9am before being seen at East Ham tube station between 10:30pm and 12:30pm.
The couple appeared to be covering their faces or looking away, and kept their baby covered up each time they were spotted.
The family have no luggage as most of their belongings were destroyed in the fire, although Marten is believed to have access to substantial resources and cash.
Her father, Napier Marten - who was a page to The Queen - made a direct appeal to his daughter.
“Darling Constance, even though we remain estranged at the moment, I stand by, as I have always done and as the family has always done, to do whatever is necessary for your safe return to us,” he told The Independent.
“I beseech you to find a way to turn yourself and your wee one in to the police as soon as possible, so you and he or she can be protected. Only then can a process of healing and recovery begin, however long it may take, however difficult it may be.”
“I want you to understand that you are much much loved whatever the circumstances. We are deeply concerned for your and your baby’s welfare.”
The couple appear to cover their faces each time they are spotted Metropolitan Police
According to her father, Gordon’s criminal history is of “great concern” to their family.
Gordon, who was born in Birmingham but moved to the US with his family, was found guilty of kidnap and rape aged 15 in 1990.
He was jailed for 20 years and was deported from the US in 2010.
The couple reportedly started their relationship in 2016 - the year Marten dropped out of drama school – and has been estranged from friends and family ever since.
Detective Superintendent Lewis Basford, who is leading the investigation, said: “We are extremely concerned that a newborn baby – less than a week old at the time on 7 January – has been exposed to sub-freezing cold temperatures if Mark and Constance have been camping out somewhere as our evidence suggests.
Marten and Gordon went missing on January 5 Metropolitan Police
“No child, especially a tiny, newborn baby, should be forced to endure such dangerous, potentially life-threatening, conditions.
“This is why it is absolutely vital that anyone with information about their whereabouts contacts us as a matter of urgency – whether it is with a recent or older sighting. Every piece of information is crucial to enabling us to find the baby and ensure it is okay.
“My officers will continue working tirelessly behind the scenes to piece together the family’s movements and current whereabouts. It could be that they are trying to blend in with homeless communities, either here in London or further afield, or they could be camping in more rural or wooded areas.
"They could be absolutely anywhere in the country. Please keep your eyes peeled, especially while you are out and about in waste ground or beauty spots, or while you’re walking the dog, and report any information, no matter how insignificant you think it is, to us.”