A woman has been arrested on suspicion of concealing a birth, neglect and infanticide after a dead baby was found outside a Notting Hill church.
It follows an appeal by police to trace the mother of the newborn baby boy found inside a Marks and Spencer bag near All Saints Church last week.
The woman, aged in her 30s, was safely located and arrested on Saturday, the Metropolitan Police said.
The woman, who officers believe is the baby’s mother, was immediately taken to a nearby hospital for treatment and to ensure all necessary medical care was provided to her, a police spokesperson said.
She currently remains in hospital.
A forensic post-mortem will take place later this week, which will help officers understand more about the baby boy’s death, the Met said.
At this time officers remain open-minded about the circumstances.
A council refuse worker found the black bag containing the infant outside the church, off Talbot Road, at 12.46pm on Tuesday, March 25.
Superintendent Owen Renowden, who leads policing for Kensington and Chelsea called the arrest “a significant development”.

He said: “This is an ongoing, fast-paced investigation, with officers working tirelessly to ascertain the circumstances of the baby boy’s death.
“We believe that the woman is the baby’s mother and I am reassured that she is receiving the support she needs, while officers continue their work to understand what took place.
“I recognise that the news of this arrest may cause concern among our community, but when dealing with investigations of this nature our priority is to ensure the welfare of all involved and ensure that all lines of enquiry are fully explored.
“I appreciate the high level of attention that this investigation has received, but we politely ask for the public not to speculate.
“Although this is a significant development, we are still appealing for anyone with any information to contact police on 101 or at @MetCC quoting CAD1879 of 26 March.”
Members of the public have paid their respects to the baby, leaving flowers, messages and a stuffed toy outside the church.

A lighted candle was left on a ledge outside the church, with a note which read: “God bless the little Baby x.”
Speaking last week after the discovery, Superintendent Owen Renowden described the discovery as “tragic”.
There is nothing to suggest that the baby found dead in a shopping bag in west London is related to three children abandoned in London across eight years, it is understood.
Police are still appealing for information on 101 or at @MetCC quoting CAD1879 of 26 March..