The search was continuing today for an 18-month-old girl who was taken from a police station by a mystery woman.
Scotland Yard released CCTV footage of the woman who turned up at Walworth police station in south-east London saying she was a friend of the toddler's mother.
The girl, Audrey Nyanor, is black and of Ghanaian heritage, according to police.
When last seen she was wearing pink trousers, a pink coat and a multi-coloured pink and white hat.
A Metropolitan Police spokesman said the child went missing after officers went to an address in De Laune Street, Walworth, on Thursday to make inquiries about a man wanted for failing to appear at court.
He was not in but police arrested the girl's 36-year-old mother in connection with alleged immigration offences.
The mother and child were taken to Walworth police station, where officers spoke to family members and friends to arrange for Audrey to be looked after.
The spokesman said: "At approximately 10.30am a woman attended the police station purporting to be a 46-year-old friend of the mother.
"Subsequently it became apparent that the woman was not the same person who had been organised to pick up the child.
"As a result a police investigation began to find Audrey, and to identify and trace the woman who took her.
"Whilst there is no evidence at this stage to suggest that Audrey has come to any harm we are very concerned that she remains missing and we are making every effort to ensure she is safely returned."
Police issued images of the woman at the police station and at Elephant and Castle underground station, where she was pictured carrying Audrey.
She is described as black, believed to be of Ghanaian heritage, of medium build with short black hair.
She was wearing a bright red coat and dark knee-length boots.
Audrey's mother was later released on bail.
Six people have been arrested in connection with the investigation, according to the Met.
Anyone with information should call the incident room on 020 8721 4906 or Crimestoppers on 0800 555 111.