Between the hours of 10.30pm on Saturday, 6 February and 12.25am on Sunday, 7 February an unidentified vehicle collided with a pedestrian on the B412, North Pole Road at the junction with the A219, Scrubs Lane and Wood Lane.
Officers and the London Ambulance Service attended the scene.
The pedestrian was taken by the London Ambulance Service to a west London hospital; she continues to receive treatment for her injuries.
The driver and a possible passenger of the vehicle briefly stopped at the scene before driving off without giving their details.
Police are keen to speak with anyone who witnessed the collision or captured it on dash cam.
Anyone with information is asked to contact the Met’s Prosecutions Team via 101 quoting reference Cad 235/07Feb.