Detectives from the Roads and Transport Policing Command are investigating a collision in Havering.
Police were called by London Ambulance Service at 07:28hrs on Monday, 24 December to reports of a vehicle in collision with a pedestrian on Hilldene Avenue, Harold Hill.
Officers and London Ambulance Service attended.
At the scene, outside St Francis Hospice, a van had been in collision with a 28-year-old woman. The woman suffered a head injury and was taken by LAS to an east London hospital. Her injury is potentially serious, and officers await an update as to her condition when the injury has been fully assessed.
The driver of the van stopped at the scene. No arrests have been made.
Investigators from the Serious Collision Investigation Unit, based at Chadwell Heath Traffic Garage investigate.
Anyone who witnessed this collision is asked to contact officers on 020 8597 4874, or by dialling 101 and quoting CAD1241/24DEC.