A 20-year-old woman is in critical condition in hospital after being hit by a marked London Metropolitan Police vehicle.
The accident happened on Warwick Road, near the junction with Kensington High Street in west London, at about 21:55 BST on Tuesday.
She was treated at the scene before being taken to a central London hospital where she remains in a critical but stable condition.
It is not known whether the police car was responding to an emergency call.
Scotland Yard said the Directorate of Professionals Standards had been informed and the Independent Office for Police Conduct has launched an investigation.