Jamie-Leigh Kelly, 31, left a Family Assessment Centre in north-west London on Tuesday, 19 September with her three-year-old daughter and new-born baby boy.
The children are under care orders and should not have been removed from the Colindale address which provides 24-hour social care support for vulnerable mothers and children.
Around 19:40hrs Jamie-Leigh left the address with the children against the wishes of staff, who were unable to prevent her from putting the children into a blue Ford Fiesta which then drove away at speed.
From CCTV enquiries, police believe the driver was a woman. She is yet to be identified and the blue Ford Fiesta is yet to be located – an image of the car has also been released by police.
Jamie-Leigh has links to Thurrock in Essex and most recently Havering, east London, which is why the Met is leading the enquiries.
Detective Superintendent Lewis Basford who leads the Met’s Public Protection command in East Area, said:
“We are extremely concerned about the welfare of Jamie-Leigh and her children, one of whom is less than one-month-old.
“Jamie-Leigh, I am making a direct appeal to you to contact with us so we can ensure the children are safe and well. We know you have no intention for the children to come to harm, so we are asking you to please pick up the phone and have a conversation with us so we can meet with you. The baby may need medical care as he is new-born, so please put him first and contact us on 020 7175 0793.”
Detective Superintendent Basford added:
“I have a team of detectives carrying out extensive lines of enquiry alongside Essex Police colleagues, and both Thurrock and Havering local authorities have been extremely supportive as we continue efforts to locate the family.
“We believe Jamie-Leigh is being assisted, and we ask anyone in Essex or London or further afield who may have information to call our incident room without delay, or dial 999 with any real time sightings.”
On Wednesday 20 September, a man in his 50s was arrested in connection with the investigation on suspicion of child abduction and conspiracy to kidnap. He remains in custody in Essex.
There is no indication that the children have been harmed, but detectives are clearly extremely concerned about their welfare. The baby boy was born in mid-September and so as a new-born is extremely vulnerable.
Jamie-Leigh Kelly is described as white with green eyes, of slim build and 5ft4ins tall. She was wearing a white jumper or long sleeved t-shirt, white jogging style trousers and white trainers.
Please contact the Met Police incident room on 020 7175 0793 with information or call 999 immediately with live sightings.
Alternatively, information can be reported 100 per cent anonymously to the independent charity Crimestoppers on 0800 555 111. They never ask for personal details and they do not trace your device.