At approximately 1.30am on Tuesday, 24 August, officers attempted to stop a car after it had failed to stop for police in the Putney area.
The subject vehicle collided with a moped on Putney High Street close to the junction with Upper Richmond Road, SW15.
The rider was taken to hospital by the London Ambulance Service with serious injuries that are not believed to be life-threatening.
The driver was arrested at the scene.
The Directorate of Professional Standards and Independent Office for Police Conduct have been informed.