Police searching for a missing couple with a newborn baby have visited every hotel in the city where they were last seen as they try to track them down.
Constance Marten is thought to have recently given birth and neither she nor her baby have been seen by doctors.
Following a number of sightings in Essex, police said they were talking to transport companies to establish if Ms Marten and her partner Mark Gordon had left the Colchester area.
They also worked through the night reviewing hours of CCTV and visiting every single hotel and bed and breakfast in the city to find out where the family had been staying.
Det Ch Insp Rob Huddleston said the police search was "about the young child's welfare".
He appealed directly to the new mother, and said: "We know some elements of the public may see police involvement as unwelcome and I would seek to assure you that we do not wish to impose ourselves for any reason other than to make sure the newborn baby is alive and well.
"I am a parent myself and I know the bond a mother and father have with their child, but I would appeal directly to Mark and Constance to put the welfare of their child first.
"To you, Constance, medical professionals still need to assess your baby to make sure he or she is medically well and there are no underlying issues for which he or she may need help for. Indeed, medical professionals would like to examine you for the same reasons.
"Please, get in contact any way you would like to. We are here and ready to help you."
The couple first sparked concern after their car broke down near junction four of the M61 near Bolton on Thursday.
They walked towards Anchor Lane bridge, which links the Highfield and Little Hulton areas, and have been missing ever since.
Essex Police said they now had a number of confirmed sightings of the couple - who were seen at Harwich port at 9am on Saturday and in Colchester an hour later.
CCTV footage released on Saturday show Ms Marten wrapped in a large red scarf outside Harwich Port in Essex on Saturday at 9am.
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