An air ambulance was called to a collision on A206 Queens Road, Erith. near the Fish Roundabout around midday on Sunday. Diversions remain in place after one person involved was airlifted to hospital.
Police were called just before 11.30am after a man was hit by a van which then drove away from the scene.
He has been taken to hospital for treatment to his injuries.
The man’s condition is not life threatening, according to police.
Officers have since arrested a man, believed to be aged in his 30s, on suspicion of causing Grievous Bodily Harm (GBH) with intent.
Anyone with information is asked to contact Met Police on 101 or via @MetCC and quote CAD2784/19Jan.