Police are trying to find a newborn baby girl after her parents failed to cooperate with doctors who say she needs urgent treatment.
The baby, identified by police only as Baby Graham, is seven days old and is the daughter of Azara and Machel Graham.
The family lives in south London and have not been seen since a post-natal assessment on Thursday.
During that appointment, Mr and Mrs Graham were told their baby had symptoms of a serious respiratory condition and needed to be taken to A&E for an urgent assessment.
The couple failed to follow the advice and their whereabouts is unknown, Metropolitan Police said.
Baby Graham’s case is a high-risk missing person investigation and police have visited the family’s Southwark home several times in the last 24 hours.
But no trace has been found of the couple or their baby.
Detective Chief Inspector Lucy O’Connor, who is leading the investigation, said: "We are becoming increasingly concerned for the safety of Baby Graham.
"Her parents have not followed the medical advice they were given and in doing so, could be putting her health at risk.
"There will be a time and a place to explore their reasons, but right now our priority has to be the safety of this very young baby."
She added: "While we would of course ask the public to keep an eye out for Baby Graham’s parents, we believe it’s likely they are being accommodated by relatives or associates.
"I would urge those people to put the welfare of this tiny baby girl above any other loyalty they may have and get in touch with the police.
"I would also appeal directly to Azara and Machel to do the right thing and to go to the nearest A&E so that Baby Graham can get the care she needs."
Anyone who sees the baby or her parents should call police on 999 quoting reference 21MIS011809, while anyone with other information that could be useful should call 101.