A toddler who was in foster care was left on a bus in north London, it has emerged.
Passengers raised the alarm after the child was left on its own in its pushchair when its carer got off the number 491 in Enfield last Friday.
Haringey Council said an investigation was underway.
Scotland Yard says the toddler, believed to be a two-year-old, was taken to hospital for checks before being handed back to social workers.
It said a woman, who identified herself as the child's foster carer, later contacted emergency services.
No arrests have been made.
The Met added that the council was working with its child abuse investigation team.
A spokesperson for Haringey Council said: "The child was found safe and well and we are undertaking a full investigation.
"As soon as this incident came to light, steps were immediately taken to arrange a new fostering placement for the child."
Haringey Council's social services department has previously been in the spotlight over its failings in the Baby P scandal.
Peter Connelly died in 2007 after he was abused. His mother Tracey was jailed in 2009 over his death.